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Risk and Decision Making: Perspectives and Research (1982)

Chapter: PERSPECTIVES ON RISK AND DECISION MAKING

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Suggested Citation:"PERSPECTIVES ON RISK AND DECISION MAKING." National Research Council. 1982. Risk and Decision Making: Perspectives and Research. Washington, DC: The National Academies Press. doi: 10.17226/775.
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Suggested Citation:"PERSPECTIVES ON RISK AND DECISION MAKING." National Research Council. 1982. Risk and Decision Making: Perspectives and Research. Washington, DC: The National Academies Press. doi: 10.17226/775.
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Suggested Citation:"PERSPECTIVES ON RISK AND DECISION MAKING." National Research Council. 1982. Risk and Decision Making: Perspectives and Research. Washington, DC: The National Academies Press. doi: 10.17226/775.
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Suggested Citation:"PERSPECTIVES ON RISK AND DECISION MAKING." National Research Council. 1982. Risk and Decision Making: Perspectives and Research. Washington, DC: The National Academies Press. doi: 10.17226/775.
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Suggested Citation:"PERSPECTIVES ON RISK AND DECISION MAKING." National Research Council. 1982. Risk and Decision Making: Perspectives and Research. Washington, DC: The National Academies Press. doi: 10.17226/775.
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Suggested Citation:"PERSPECTIVES ON RISK AND DECISION MAKING." National Research Council. 1982. Risk and Decision Making: Perspectives and Research. Washington, DC: The National Academies Press. doi: 10.17226/775.
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Suggested Citation:"PERSPECTIVES ON RISK AND DECISION MAKING." National Research Council. 1982. Risk and Decision Making: Perspectives and Research. Washington, DC: The National Academies Press. doi: 10.17226/775.
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Suggested Citation:"PERSPECTIVES ON RISK AND DECISION MAKING." National Research Council. 1982. Risk and Decision Making: Perspectives and Research. Washington, DC: The National Academies Press. doi: 10.17226/775.
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Suggested Citation:"PERSPECTIVES ON RISK AND DECISION MAKING." National Research Council. 1982. Risk and Decision Making: Perspectives and Research. Washington, DC: The National Academies Press. doi: 10.17226/775.
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Suggested Citation:"PERSPECTIVES ON RISK AND DECISION MAKING." National Research Council. 1982. Risk and Decision Making: Perspectives and Research. Washington, DC: The National Academies Press. doi: 10.17226/775.
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Suggested Citation:"PERSPECTIVES ON RISK AND DECISION MAKING." National Research Council. 1982. Risk and Decision Making: Perspectives and Research. Washington, DC: The National Academies Press. doi: 10.17226/775.
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Suggested Citation:"PERSPECTIVES ON RISK AND DECISION MAKING." National Research Council. 1982. Risk and Decision Making: Perspectives and Research. Washington, DC: The National Academies Press. doi: 10.17226/775.
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Suggested Citation:"PERSPECTIVES ON RISK AND DECISION MAKING." National Research Council. 1982. Risk and Decision Making: Perspectives and Research. Washington, DC: The National Academies Press. doi: 10.17226/775.
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Suggested Citation:"PERSPECTIVES ON RISK AND DECISION MAKING." National Research Council. 1982. Risk and Decision Making: Perspectives and Research. Washington, DC: The National Academies Press. doi: 10.17226/775.
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Suggested Citation:"PERSPECTIVES ON RISK AND DECISION MAKING." National Research Council. 1982. Risk and Decision Making: Perspectives and Research. Washington, DC: The National Academies Press. doi: 10.17226/775.
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Suggested Citation:"PERSPECTIVES ON RISK AND DECISION MAKING." National Research Council. 1982. Risk and Decision Making: Perspectives and Research. Washington, DC: The National Academies Press. doi: 10.17226/775.
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Suggested Citation:"PERSPECTIVES ON RISK AND DECISION MAKING." National Research Council. 1982. Risk and Decision Making: Perspectives and Research. Washington, DC: The National Academies Press. doi: 10.17226/775.
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Suggested Citation:"PERSPECTIVES ON RISK AND DECISION MAKING." National Research Council. 1982. Risk and Decision Making: Perspectives and Research. Washington, DC: The National Academies Press. doi: 10.17226/775.
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Suggested Citation:"PERSPECTIVES ON RISK AND DECISION MAKING." National Research Council. 1982. Risk and Decision Making: Perspectives and Research. Washington, DC: The National Academies Press. doi: 10.17226/775.
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Suggested Citation:"PERSPECTIVES ON RISK AND DECISION MAKING." National Research Council. 1982. Risk and Decision Making: Perspectives and Research. Washington, DC: The National Academies Press. doi: 10.17226/775.
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Suggested Citation:"PERSPECTIVES ON RISK AND DECISION MAKING." National Research Council. 1982. Risk and Decision Making: Perspectives and Research. Washington, DC: The National Academies Press. doi: 10.17226/775.
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Suggested Citation:"PERSPECTIVES ON RISK AND DECISION MAKING." National Research Council. 1982. Risk and Decision Making: Perspectives and Research. Washington, DC: The National Academies Press. doi: 10.17226/775.
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Suggested Citation:"PERSPECTIVES ON RISK AND DECISION MAKING." National Research Council. 1982. Risk and Decision Making: Perspectives and Research. Washington, DC: The National Academies Press. doi: 10.17226/775.
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Suggested Citation:"PERSPECTIVES ON RISK AND DECISION MAKING." National Research Council. 1982. Risk and Decision Making: Perspectives and Research. Washington, DC: The National Academies Press. doi: 10.17226/775.
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Suggested Citation:"PERSPECTIVES ON RISK AND DECISION MAKING." National Research Council. 1982. Risk and Decision Making: Perspectives and Research. Washington, DC: The National Academies Press. doi: 10.17226/775.
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Suggested Citation:"PERSPECTIVES ON RISK AND DECISION MAKING." National Research Council. 1982. Risk and Decision Making: Perspectives and Research. Washington, DC: The National Academies Press. doi: 10.17226/775.
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Suggested Citation:"PERSPECTIVES ON RISK AND DECISION MAKING." National Research Council. 1982. Risk and Decision Making: Perspectives and Research. Washington, DC: The National Academies Press. doi: 10.17226/775.
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Suggested Citation:"PERSPECTIVES ON RISK AND DECISION MAKING." National Research Council. 1982. Risk and Decision Making: Perspectives and Research. Washington, DC: The National Academies Press. doi: 10.17226/775.
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Suggested Citation:"PERSPECTIVES ON RISK AND DECISION MAKING." National Research Council. 1982. Risk and Decision Making: Perspectives and Research. Washington, DC: The National Academies Press. doi: 10.17226/775.
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Suggested Citation:"PERSPECTIVES ON RISK AND DECISION MAKING." National Research Council. 1982. Risk and Decision Making: Perspectives and Research. Washington, DC: The National Academies Press. doi: 10.17226/775.
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Suggested Citation:"PERSPECTIVES ON RISK AND DECISION MAKING." National Research Council. 1982. Risk and Decision Making: Perspectives and Research. Washington, DC: The National Academies Press. doi: 10.17226/775.
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Suggested Citation:"PERSPECTIVES ON RISK AND DECISION MAKING." National Research Council. 1982. Risk and Decision Making: Perspectives and Research. Washington, DC: The National Academies Press. doi: 10.17226/775.
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Suggested Citation:"PERSPECTIVES ON RISK AND DECISION MAKING." National Research Council. 1982. Risk and Decision Making: Perspectives and Research. Washington, DC: The National Academies Press. doi: 10.17226/775.
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Suggested Citation:"PERSPECTIVES ON RISK AND DECISION MAKING." National Research Council. 1982. Risk and Decision Making: Perspectives and Research. Washington, DC: The National Academies Press. doi: 10.17226/775.
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Suggested Citation:"PERSPECTIVES ON RISK AND DECISION MAKING." National Research Council. 1982. Risk and Decision Making: Perspectives and Research. Washington, DC: The National Academies Press. doi: 10.17226/775.
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Suggested Citation:"PERSPECTIVES ON RISK AND DECISION MAKING." National Research Council. 1982. Risk and Decision Making: Perspectives and Research. Washington, DC: The National Academies Press. doi: 10.17226/775.
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Suggested Citation:"PERSPECTIVES ON RISK AND DECISION MAKING." National Research Council. 1982. Risk and Decision Making: Perspectives and Research. Washington, DC: The National Academies Press. doi: 10.17226/775.
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Suggested Citation:"PERSPECTIVES ON RISK AND DECISION MAKING." National Research Council. 1982. Risk and Decision Making: Perspectives and Research. Washington, DC: The National Academies Press. doi: 10.17226/775.
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Suggested Citation:"PERSPECTIVES ON RISK AND DECISION MAKING." National Research Council. 1982. Risk and Decision Making: Perspectives and Research. Washington, DC: The National Academies Press. doi: 10.17226/775.
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Suggested Citation:"PERSPECTIVES ON RISK AND DECISION MAKING." National Research Council. 1982. Risk and Decision Making: Perspectives and Research. Washington, DC: The National Academies Press. doi: 10.17226/775.
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Suggested Citation:"PERSPECTIVES ON RISK AND DECISION MAKING." National Research Council. 1982. Risk and Decision Making: Perspectives and Research. Washington, DC: The National Academies Press. doi: 10.17226/775.
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Suggested Citation:"PERSPECTIVES ON RISK AND DECISION MAKING." National Research Council. 1982. Risk and Decision Making: Perspectives and Research. Washington, DC: The National Academies Press. doi: 10.17226/775.
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Suggested Citation:"PERSPECTIVES ON RISK AND DECISION MAKING." National Research Council. 1982. Risk and Decision Making: Perspectives and Research. Washington, DC: The National Academies Press. doi: 10.17226/775.
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Suggested Citation:"PERSPECTIVES ON RISK AND DECISION MAKING." National Research Council. 1982. Risk and Decision Making: Perspectives and Research. Washington, DC: The National Academies Press. doi: 10.17226/775.
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Suggested Citation:"PERSPECTIVES ON RISK AND DECISION MAKING." National Research Council. 1982. Risk and Decision Making: Perspectives and Research. Washington, DC: The National Academies Press. doi: 10.17226/775.
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Suggested Citation:"PERSPECTIVES ON RISK AND DECISION MAKING." National Research Council. 1982. Risk and Decision Making: Perspectives and Research. Washington, DC: The National Academies Press. doi: 10.17226/775.
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PERSPECTIVES ON RISK AND DECISION MAKING When people say they must make a decision involving risk, they often mean that the decision involves the possibility of an adverse consequence. This report does not deal with risk and decision making so broadly de- fined, since almost every important decision in life entails the possibility of an adverse consequence. To narrow its task, the committee concentrated on those decisions involving the possibility of adverse effects for human health, safety, and the environment. This narrowing does not reflect a belief that other types of risks are less important--certainly the personal risks in a career choice or the economic risks faced by people in business are no less important. The focus reflects the committee's expertise and, more important, a growing public awareness of and concern about adverse conse- quences to human health, safety, and the environment. INCREASED LONGEVITY AND RISING PUBLIC CONCERN ABOUT RISK The increases in average life expectancies for Americans have not lessened their concern with risks and may even have increased it. The evidence for changing mortality and morbidity is worth examining briefly as a base for

2 gauging actual risks; further exploration of possible reasons why concerns with risk have not abated may im- prove understanding of the perceptions of risk. The first sentence of a recent report (U.S. Surgeon General, 1979) proclaimed that "the health of the Ameri can people has never been better." ~' -Lee surgeon general documents improvement in many indices of illness, non- fatal conditions, and mortality. We would like to emphasize primarily the progress made against mortality, since, in the absence of a comprehensive statistical measure of risk, the single best indicator is perhaps that provided by mortality statistics. The decline in U.S. mortality rates since the turn of the century has been steady and, on a cumulative basis, dramatic. Life expectancy at birth has increased in the United States from 47 years in 1900 to 74 years in 1979. The age-adjusted death rate has fallen by two-thirds, from 18 per 1,000 in 1900 to under 6 per 1,000 in 1979. The probability of "early" death--death before age 65--has declined from over 60 percent at 1900 mortality rates to under 25 percent at 1979 rates. Mortality reductions in the 1970s have been espe- cially impressive. For example, in the United States the likelihood that a person age 65 would live at least another decade has increased by 14 percentage points from 1900 to 1970 (from 55 to 69 percent) and then by another 5 percentage points by 1979 (to 74 percent). In 1979, the age-adjusted death rate at all ages was 18 percent lower than it was 9 years earlier. Similar im- provements have occurred in other countries as well, including dramatic ones in the less developed countries considered as a group. According to one poll (Louis Barris and Associates, 1980) most Americans believe life is getting riskier: 78 percent of the public surveyed agreed that "people are subject to more risk today than they were twenty years ago" (p. 9~; only 6 percent thought there was less risk. Furthermore, 55 percent felt that "the risks to society stemming from various scientific and technologi- cal advances will be somewhat greater 20 years from now than they are today" (p. 10), as opposed to only 18 per- cent who felt that the risks will be somewhat less. The degree of concern about risk has increased sharply since about 1960. For example:

3 . . . . . . . The enactment of more than 30 major laws by the U.S. Congress from 1965 to 1980 (and numerous laws by state legislatures) aimed at coping with occupational, consumer product, environ mental, transportation, and other sources of risks; The establishment or strengthening of at least a dozen regulatory agencies with broad legal authority and rising budgets throughout the 1970s; The growth of litigation related to health, safety, and environmental risks in the 1970s in both the tort-liability system and the arena of judicial review of agency decision making; The creation and growth of numerous public interest groups concerned with health, safety, and environmental risks, a movement that has significantly changed the politics of risk and the politics of regulation; The emergence of various forms of business sponsored efforts to improve risk management by the private sector, to publicize these efforts, and to coordinate them with those being taken by local, state, and federal governments (for examples of increasing corporate efforts to control risks, see U.S. Department of Commerce, 1980~; The expanded media coverage of scientific find ings about risks, corporate risk .anagement activities, and political activity related to risk; m e increase in funding for health, safety, and environmental research and the emergence of a relatively new field of "risk analysis." SOME POSSIBLE INTERPRETATIONS Multiple hypotheses have been proposed for the apparent contradiction between increased longevity and increased concern with risk.1 While several hypotheses are given below, there are undoubted!, others. . iSeveral reviewers and committee members comment that they feel no compelling reason to explain "the apparent contradiction between increased longevity and increased

4 Mortality Differentials One source of concern about risk may be a growing reali- zation that certain groups in society suffer from higher than ordinary rates of early death. Despite historical progress, it is increasingly apparent that there are numerous opportunities for further longevity gains. For example, two types of mortality differentials suggest that it may still be possible to substantially reduce mortality rates in the United States: the high rates of mortality among disadvantaged groups in the United States and the higher rates of mortality for the entire U.S. population compared with that of many other developed nations. Blacks, Hispanic Americans, American Indians, and the poor and poorly educated in general suffer from sub- stantially higher death rates than do middle- and upper- class whites. mese disparities should be understood in the context of a period of dramatic improvement, at least for some disadvantaged groups. Between 1950 and 1975, for example, both whites and nonwhites experienced sharply reduced rates of infant mortality as well as general increases for all ranges of age-specific mortal- ity except for the very old. Although these improve- ments were greater for nonwhites than for whites, mor- tality differentials between the two groups remain large. For example, if current mortality rates remain unchanged, two of five nonwhites will die before reach- ing age 6S, compared with one of five whites. Although data are sparse, mortality and morbidity rates among migrant workers in the United States appear to be espe- cially high. The United States fares poorly compared with other developed countries in terms of a variety of health in- dicators, including infant mortality, life expectancy, cardiovascular disease rates, cancer death rates, and homicide rates. For instance, the United States is 26th on a list of countries in the probability of death be- fore age 6S. In terms of reported mortality rates, the concern about risker They go on to say that in their opinion there i8 no real contradiction because of reasons A, B. or C. Not all these critics, however, agree on A, B. or C. "An apparent contradiction" is an individual opinion: some believe it; others don't. - , v ~ . .

United States ranks close to countries with less than half the U.S. per-capita income. The likelihood of death before age 65 for selected countries is: Rank Country Probability 1 Sweden .183 10 Canada .235 26 United States .275 37 Mexico .419 41 Liberia .665 U.S. whites, however, have a probability of death before age 65 of .412. Persistent differences in life expectancies, between nations and between different groups in the United States (e.g., whites and nonwhites), may mean that, for the lagging populations, achievable mortality gains are not being realized. These attainable gains also imply inequities in the distribution of risk: some croups carry higher burdens of risks. ~ r ~ tality differentials and the linked issue of equity in the sharing of risks are surely part of the reason for increased concern with risk despite general increases in life expectancies. Smoking and Drinking The persistence of mor Some mortality gains are attainable through individual action. For example, alcohol consumption ranks second to cigarette smoking as a behavioral cause of death. The report by the U.S. surgeon general (1979) estimates that "alcohol misuse is a factor in more than 10 percent of all deaths in the tinited States" and cigarette smok- ing is a factor in 17 percent of all deaths. Nonethe- less, alcohol abuse produces social problems that, in at least two respects, are more serious than those problems caused by cigarette smoking. First, alcohol abusers impose substantial costs on others (especially on family and close friends) through homicide, suicide, spouse beating, child abuse, and motor vehicle accidents. . . . . Second, alcohol abuse is a major cause of death at younger ages. For instance, the surgeon general reports that "alcohol-related accidents are the leading cause of death in the 15 to 24 age group."

6 Cigarette smoking remains a major health problem, despite reductions in the numbers of Americans who smoke. As the surgeon general's report emphasizes: Cigarette smoking is clearly the largest single preventable cause of illness and pre- mature death in the United States. . . . Cigarette smokers have a 70 percent greater rate of death from all causes than nonsmokers, and tobacco is associated with an estimated 320,000 premature deaths a year. Another 10 million Americans currently suffer from debilitating chronic diseases caused by smoking. In recent years, both the scientific and policy aspects of the smoking problem have become more compli- cated due to greater awareness of the interaction of smoking with other contaminants, such as asbestos in the workplace and community air pollutants.2 Increasing and Emerging Risks The declining incidence of age-specific mortality fails to reflect some especially pernicious risks that may be increasing or emerging, including the risks of crime, environmental contamination, and nuclear war. Since many emerging risks could have been selected for discus- sion by the committee, we have highlighted those that polling data suggest are of most concern to Americans (see Louis Harris and Associates, 1980~. cat- - r-~ ZThat awareness. as one committee member comments, does not always extend to an awareness of the relative impacts of smoking alone versus smoking in combination with other factors. Thus, if no one smoked tobacco, the proximate cause of 320,000 deaths a year, including most of the deaths of asbestos workers, would be eliminated. If, however, asbestos exposure had never occurred, only about 4,000 deaths would be eliminated, of which only a few hundred could be additional to those eliminated by stopping smoking.

7 Crime For many Americans, especially those living in inner cities, crime represents one of the most significant risks of daily life. Since the early 1960s, violent crime rates (murder, rape, robbery, and assault) have increased sharply, and survey data reveal that crime Is one of the risks of most concern e. O Americans. High and rising rates of crime impose psychic costs on individ- uals, which in turn impair the sociological health of communities. Moreover, (except for murder) these in- creasing crime rates are not directly reflected in longevity statistics. For many Americans, the risk of crime is especially serious and immediate. Environmental Contamination Although considerable progress has been made in the past 20 years in improving certain aspects of air and water quality, serious environmental problems confront us, and some environmental threats are increasing. Polling data indicate that Americans continue to be concerned with environmental degradation. That concern is seconded by other indications of continuing and new problems. For example: . . o While national emissions and ambient levels of sulfur dioxide and total particulates in the air have declined since the 1960s, there may even be increases in some geographical areas for sul- fates and fine particulates, two pollutants that may pose greater risks to human health than sul- fur dioxide and total particulates; U.S. emissions of sulfur and nitrogen oxides are combining with water vapor in the atmosphere to produce acid rain. As a result, the pH value of precipitation in the United States and other countries is frequently dropping well into the acid range, posing threats to fish, wildlife, and other organisms; The production of chemicals increased by a factor of 10 between 1945 and 1975, an indica- tion of economic growth and prosperity; this trend has also contributed to the growing prob- lem of safe disposal of hazardous wastes; i, ~e ~

8 · The burning of fossil fuels by the United States and other countries is raising the amount of carbon dioxide in the atmosphere, which is now expected to significantly warm the global sur- face and thereby to affect regional climate patterns. These and other persistent, growing, or emerging environmental risks are not likely to be readily dis- cernible in historical or current mortality figures, due to long latency periods before adverse effects occur and the difficulties of distinguishing environmentally caused deaths from those caused by other factors. The increased manufacture and use of toxic chemicals and the rise in the incidence and the death rate from some can- cers have been a source of controversy. Whether there is a causal relationship between these two trends re- mains an issue involving large scientific uncertainties and considerable dispute among experts.3 Recent survey data indicate that "chemicals" are a major source of increased perceived risk among the pub- lic. m is finding underscores the importance of making the level of this risk more precise and of explaining it clearly. Nuclear War Although the vast nuclear stockpiles in the United States and the Soviet Union may have deterred a major military confrontation between these nations, such weapons have also created a fear of quick and immense destruction. The perceived risk of a nuclear calamity varies and seems to correlate with the existing state of tension between the superpowers. For example, after the signing of the Limited Test Ban Treaty in 1963 and of SALT I in 1972 the perceived risk was much lower than during the period of high tension created by the Cuban missile crisis. At this time, the uneasy relationship between the United States and Soviet Union combines with 3A committee member observes that although most ex- perts believe that there is no important causal rela- tionship, the issue is so important that they tend to be very cautious in their statements. The very '~edging" raises concern.

9 the volatility of the Mideast to make the possibility of a military confrontation escalating to a nuclear war a substantial threat.4 Although it is not directly measurable, the risk of nuclear devastation has probably increased since 1972 as a consequence of increased U.S./Soviet hostility and continued emphasis on nuclear weapons development in both countries. The emergence of China as a nuclear nation and the potential prolifera- tion of nuclear weapons in the Third World have added new dimensions to the threat of nuclear war. The risk of nuclear war is identified in this report for two reasons. First, it is crucial to identify those major risks that are not reflected in mortality in- dices. For example, the historical progress in increas- ing life expectancy does not take into account the per- sistent danger of nuclear war. Even if longevity is increasing, the probability of death may be constant or increasing if the probabilities of nuclear war are in- creasing. Second, the polling data on public concern about risks indicate the importance of global political instability, a concern that may take on greater signifi- cance due to nuclear armaments. The risk of nuclear war is fundamentally different from other daily risks of life for at least three rea- sons. Nuclear war threatens not only individuals but also current civilization and ecosystems. The risks of nuclear war are largely beyond individual control and may even be beyond one nation's control. Finally, rela- tively little is known about the likelihood of a nuclear confrontation's becoming an all-out exchange, the possi- bility of limiting escalation, or the degree of devasta- tion that would result from any nuclear war. These un- certainties provide an opportunity for the likelihood or consequences to be sensationalized or suppressed. ~e ~ Nuclear Power Polling data indicate that the risks of nuclear power are of considerably less concern to Americans than those 4A committee member comments that the increased mili- tary aggressiveness of the United States may reduce the probability of nuclear confrontation, because it signals our determination to remain firm.

10 of nuclear war (Louis Harris and Associates, 1980~.5 Moreover, these concerns differ not only in magnitude but also in kind. Rather than annihilation, the risks perceived by most Americans are more local, as in a meltdown catastrophe, or more subtle, as in genetic damage to future generations resulting from long-tenm exposure to ionizing radiation from nuclear plants or from repositories for their radioactive wastes. Also, large-scale nuclear power plants symbolize for some the imposition of a relatively new technology, which fosters an increasingly centralized and complex society in which the power of the individual is dimin- ished. Such concerns mean that debates on the course of nuclear power are inevitably flavored not only by tech- nical, economic, and political concerns but also, more strongly than in other issues, by philosophical ones. That debate continues to be vigorous in the United States and abroad. At one extreme, advocates argue that nuclear power provides an almost unlimited, low-cost energy resource essential in the transition from non- renewable fossil fuels to renewable forms, such as solar power. At the other extreme, opponents see nuclear energy as ushering in the potential for worldwide calamity threatening human survival; they link nuclear power with nuclear weapons and nuclear war, through the proliferation of new nuclear powers and through national and subnational terror; more important, they link the acceptance of nuclear power with acceptance of nuclear weapons and their use in another war. Those advocating nuclear power argue that the knowledge of nuclear fis- sion, even how to make bombs, is widespread. In this sense the nuclear genie is out of the bottle. If a country wants nuclear weapons, the proponents of nuclear power argue, it can acquire the fissionable materials needed via research reactors rather than power reac- tors. Also, despite the Three Mile Island accident, they further argue that nuclear power has proven safer and more environmentally benign than any other form of energy, predicting that this record can be maintained with continuing vigilance. Opponents challenge those . bA reviewer argues that perhaps 'the risks seen by the public are of the same kind, not different, and that this has been, in fact, one of the major stumbling blocks to the public acceptance of nuclear power."

11 predictions, arguing that with wider use the chance for accident and for radioactive contamination will inevi- tably rise. Lay people as well as scientists are split on those issues. Even though public referenda have shown that the bulk of public opinion lies well within the extreme points of view given above, public apprehension about nuclear power remains high. These uncomfortable strains in the development of nuclear power undoubtedly contrib- ute to apprehension in a significant sector of society and hence to its belief that life is becoming riskier, despite mortality statistics to the contrary. _ RISK PERCEPTION Anxiety about risk is a product of people's beliefs and attitudes. People often form such beliefs and attitudes on the basis of incomplete and often biased information using fallible modes of inference, which sometimes result in systematic distortions and misperceptions of reality. These heuristics, although sometimes useful and convenient, result in systematic distortions and misperceptions of reality. For example, scientific progress identifies new risks, which are reported to the public. There are reports on the risks of the Three Mile Island accident hazardous chemical wastes in the Love Canal, DC-10s, benzene, saccharin, asbestos, tampons, PCBs, the pill, . recombinant DNA, nuclear waste, and so forth. These reports may make certain risks more memorable or imagin- able, thereby increasing perceived probabilities of risk regardless of the total scientific evidence about or trends in actual indices of risk. If this phenomenon is occurring on a large scale, it may explain part of the rising public concern about risk. As people become better informed about various health and safety risks, levels of concern can be expected to rise.6 This process is accelerated by scientific advances that detect more and more previously unknown sources of risk. tA reviewer remarks that better information can sometimes indicate decreased risks. While perceptions of existing, real risks change, scientific advances may introduce new risks and alleviate old ones.

12 In addition, certain attributes of risks that con- cern people are not reflected in mortality statistics or in typical quantitative risk assessments. The cata- strophic nature of some risks and the uncontrollability of other risks are not easily communicated by simple tallies of deaths and injuries. This is not an argument against quantitative risk estimates but rather an argument for a broader risk analysis in combination with numerical risk estimates. Consider two examples. me expected annual number of deaths from nuclear power plants may be extremely small,7 but some people may be especially concerned about the catastrophic nature of a major accident if it were to occur. The number of an- nual highway deaths far exceeds the annual expected death toll from nuclear plant meltdown, yet there is a widespread perception that highway accident risks are more controllable by the individual, even though one- fourth of the accidents occur in such a way that they cannot be controlled. Factors such as the geographical concentration of risk and the individual controllability of risk influence social concern about risk even though such factors do not influence typical quantitative risk assessments. (On perceptions of controllability, see Wilson 1979; on perceptions of catastrophe in nuclear power, see Slavic et al., in press.) As per-capita income in a society rises, the desire for risk reduction will generally increase. Rising levels of affluence in the United States may therefore be contributing to accelerating public concern about risk. In addition, aspirations are related to faith in science And technology. While technological progress often creates new risks, it also provides society with new opportunities to reduce old and emerging risks. If expectations about science and technology have increased in recent decades, it may explain part of the increasing attention to risk. Finally, while many of the risks of the early l900s appeared to be acts of nature or God, today's risks may appear to be more subject to individ- ual human control. The fatalistic attitudes of the past are increasingly, though unevenly, replaced by concern about risks viewed as manageable. Public concern about risk may be rising because business and government, the major risk-management _ . . 7A committee member asserts that the problem is more that people don't believe this.

13 . institutions in society, have suffered from a loss of public confidence in the past 20 years. The decline in public confidence in businesses during the late 1960s and early 1970s is well-documented by survey data. While in 1968 more than two-thirds of Americans believed business was, according to one poll, striking a "fair balance" between profits and the broader interests of the public, only 16 percent believed it by 1976 (see White and Hochstein, 1980~. Increased public skepticism of government began in the Vietnam years of the 1960s. ~. . and was parade by the perceived failure of the Great Society programs, accelerated by the Watergate scandal, and remained throughout the 1970s at a high level. Whatever the reasons for the decline in public con- fidence in business and government, the trend has been syncronous and may have interacted with rising aspira- tions for risk reduction and with perceptions of in- creasing and emerging risks. If this speculation is true, people may have begun to suspect that although the resources and technology exist to reduce old and emerg- ing risks, risk-management institutions are incapable of performing the requisite tasks. In the late 1960s such skepticism was not reflected in the optimistic attitude toward the growth of regulation, but by the late 1970s skepticism in the regulatory approach to risk reduction had demonstrably increased Mitchell, 19793. In summary, the types of risks we consider have changed in kind, and we have new perceptions of old and new risks. The change in kind has been under way since the beginning of the century, with, for example, the gradual displacement of infectious diseases such as typhoid fever or smallpox by chronic diseases such as heart disease and cancer. Furthermore, new sources of risk have emerged that individuals may feel powerless to prevent; nuclear war is the notable example. At the same time, several forces have altered people's percep- tion of risk: the intensified reporting of risks in the media, which, sometimes justified and sometimes not, magnifies people's concerns; the loss of faith in insti- tutions ostensibly created to deal with risk; and the growth of a complex, highly technological society that is interdependent in its functioning and that reduces the perception of individuals that they can control events.

14 RISK-GENERATING AND RISK-COPING PROCESSES In this report, the phrase the "generation of risks" is used broadly to refer to the manner by which risks are caused, created, triggered, and aggravated in society. me phrase refers not only to the chemical, biological, and physical sources of risk but also to economic, behavioral, and organizational factors that create risks. Similarly, the phrase "coping with risks" is used broadly to refer to the many ways in which individ- uals and organizations respond to risks in life. These responses are often deliberate preventive actions; more often, however, they are reactive, ad hoc actions by individuals, businesses, agencies, legislatures, courts, etc. Careful study of both risk-generating and risk- coping processes is essential to improving society's ability to control risks in an optimal or acceptable manner. The Generation of Risks The committee's investigation of risk generation sug- gests that (1) not all risks require social interven- tion, (2) the rationales for social intervention are strikingly different depending on how a risk is per- ceived to be generated, and (3) although society fre- quently must respond to risks without conclusive scien- tific evidence about causation, the development of ef- fective, long-term coping strategies is possible only if the generation of risks is better understood. To pro- vide organization to the analysis of risk generation, the committee used a simple classification scheme (see Figure 1~.8 Although it is an imperfect model of risk 80ne member of the committee, while agreeing that risks can be classified in this way, argues that other classifications may be more useful. He argues that the important classifications are the way the risk is cal- culated and the magnitude of the risk. Specifically: 1. Can the risk be directly calculated from histor- ical data with a clear cause and effect? 2. Is the risk a historical one, but with a weak cause and effect relationship, so that it is not easily recognized?

15 generation, the scheme is useful in elucidating some broad perspectives about social intervention and risk- coping strategies. Social Intervention to Reduce Risks: When and Why? Some risks, such as those generated by criminal behavior and by certain production externalities, are widely re- garded as important social problems of widespread public concern. In both cases, those who incur risks are suf- fering from an imposition by other individuals or pro- ductive enterprises, an imposition that the victims of such risks cannot easily control. In contrast, the risks generated by self-hazardous behavior--although they may produce more deaths, injuries, and illnesses than those created by productive enterprises or by criminals--are not so widely regarded as an appropriate subject of social intervention. Advocating social in- tervention to reduce risks from self-hazardous behavior quickly triggers debates about freedom and the role of government in society. Similar concerns, albeit to a lesser degree, apply to co-generated risks (see Figure 1) . There are certainly plausible arguments both for or against intervention in self-hazardous behavior. The self-hazardous aspects of smoking, alcoholism, suicide, motor vehicle accidents, obesity, etc. are of such an enormous magnitude that they sometimes defy explanation 3. Risks of new technologies have to be calculated by factoring the problem, such as is done in "event free" analysis. 4. Some risks have such a delayed cause and effect relationship that direct calculation is very hard; cancer is in this category. The risk has to be calculated by an analogy of people and experimental animals. Each of these categories leads to difficult strategies for risk prevention and to different public percep- tions. Each also leads to a great deal of argument about words; for example, the risk posed by air pollu- tion falls in the second category. That risk is often discounted as being "unknown" or 'hypothetical" even if the magnitude is as large as other risks in the first category.

16 FIGURE 1 The Generation of Risks: A Simple Classification Scheme Self-Hazardous Behavior: Situations in which an . individual creates and incurs the same risk. Illustra- tive examples: smoking, alcohol abuse, not using seat belts, or hang gliding. Co-generation of Risks: When the combined actions of two or more parties impose a risk on one of the parties. Illustrative examples: risks imposed on a worker resulting from combined actions of worker and employer or risks imposed on consumers by the combined actions of producer and consumer. Risks Generated by Production Externalities: When productive enterprises generate risks that are incurred by people not directly involved in the production or consumption of a good. Illustrative examples: air and water pollution, nuclear accidents, and hazardous wastes. Risks Imposed by Particular Individuals on Others: When individuals generate risks that are imposed on others. Illustrative examples: crime, speeding, drunken driving, child abuse, and smoking in public places. Risks Generated by Nature: A category including natural hazards such as earthquakes, droughts, and floods as well as certain physical conditions generated by nature (e.g., diseases of old age, genetic mutations, and disease from natural ionizing radiation). Of course, the degree of possible risk can be tempered by individual or social actions: deciding to live near a fault zone, earthquake-resistant design or construction, construction of dams, and so on. Risks Generated by Economic Conditions: Individuals to various itself is a risk that also creates risk for health and safety. Illustrative examples: poverty-induced disease and unemployment-induced stress. Risks Generated by Government Policies: Public policies sometimes subsidize, encourage, or force individuals or organizations to create risks. For example, some national energy policies create risks to human health, safety, and the environment as well as to national security and the likelihood of war. and communities create and incur risks due economic conditions. Financial insecurity

17 in terms of purely "rational" behavior. Many but not all adult smokers, drinkers, overeaters, and nonexer- cisers, after due and deliberate reflection, like to do what they are doing (at least in the short run), making the rationales for intervention to influence behavior complex and controversial. The rationales for social intervention can be compelling when the social costs of self-hazardous behavior are considered, such as the effects on children and adolescents. mis is particu- larly important for those risks that are habit-forming, such as taking drugs and smoking. Moreover, some self- hazardous activities, such as smoking and drinking, also create risks for others (i.e., passive smoking, fires, and accidents), strengthening the case for some form of social intervention. However, since some self-hazardous behavior is often the result of conscious, informed de- cisions by adults who bear the consequences of their actions, the case for intervention becomes complex, requiring the balancing of opposing objectives. The class of co-generated risks is somewhat of an intermediate case with regard to justification for social intervention. Workers and consumers co-generate risks with employers and sellers; furthermore, in their consensual nature, co-generated risks are somewhat similar to self-hazardous behavior. But workers and consumers are often unaware of the risks they incur. For example, employers and sellers sometimes have an incentive to withhold information about risks in order to prevent subsequent liability or regulation. The information problem may be particularly acute for con- sumers engaged in one-time purchases or for consumers and workers who are exposed to risks that become appar- ent only after long latency periods. For these reasons and others, co-generated risks should be important tar- gets of social intervention. The Linkage Between Risk Generation and Coping Strategies The more society learns about the generation of risks, the more competent it can be in designing coping strate- gies. For example, better empirical evidence about the relationship between economic conditions and risk would be quite valuable to policy makers. How effective is economic prosperity in reducing risks compared with more direct strategies to reduce risks, such as regulation, liability, and health warnings? This knowledge would be

18 useful to legislators in deciding how much of the na- tion's limited resources to devote to direct risk-coping strategies as opposed to policies to promote general economic well-being. Quantitative estimates of the prevalence of consumer or employee misperception or ignorance of product or occupational risks would also be useful to policy mak- ing. To what extent do sellers and employers have in- centives to withhold, distort, or selectively present information about risks to consumers and workers? The case for social intervention to reduce co-generated risks rests significantly on the misinformation hypoth- esis; that is, the extent of misinformation-~whether it arises from ignorance, ineffectiveness, intentional sup- pression, or falsification--influences the rationales for and against intervention and the choice of risk- coping strategies. A third, broader issue is the insights that can be gleaned for managing our risk problems from studying how other societies manage theirs. Do predominantly market economies, for example, generate more, less, or differ- ent risks than predominantly nonmarket economies? Are democratic political systems more or less effective than authoritarian regimes in controlling risk-generating processes? Risk-generating and risk-coping processes may be fundamentally influenced by different political and economic systems, but little systematic research has explored this possibility. Coping With Risks Many important decisions about taking and mitigating risks are made by individuals in their personal lives, for example: fastening seat belts, driving while intoxicated, smoking cigarettes, taking the medicine prescribed to control high blood pressure, taking one's children to be vaccinated, wearing safety glasses and respirators in the workplace, staying in bed when sick, obeying speed limits, buying health and life insurance, working as a steeplejack, driving a subcompact rather than a large car, and living on a flood plain or in an earthquake fault zone. Other important decisions about risks are made by various institutions in society, as businesses, unions, public interest groups, govern- ment agencies, courts, and legislatures. ~ such

19 Some methods for coping with risks or mitigating them, such as insurance policies, medical care services, legal remedies, and scientific research, have broad ap- plications. m ese are generic coping strategies. In- surance converts uncertain yet potentially serious financial losses into relatively small and certain financial payments. Medical services are a response to risk, but this report can only briefly acknowledge the roles these services play in preventing and curing ill- nesses and caring for the sick and terminally ill. The two most important legal remedies for risks--liability and regulation--influence the incentives of people and firms to engage in risk-generating activities. Finally, scientific research explores the nature and methods of coping with risk through, for example, biomedical re- search, safety engineering research, epidemiological research, and toxicological research. In addition to these generic coping strategies, society uses particular strategies to respond to partic- ular categories of risks. These targeted strategies are often extensions of generic coping strategies, tailored to respond to particular risk-generating situations. - Coping Strategies and the Rationales for Intervention The strategies appropriate for coping with self- hazardous behavior vary with the rationales for social intervention. If the rationale is that such behavior imposes financial costs on others through insurance policies or tax-supported public programs, then a variety of approaches to controlling those costs can be considered. If, however, society is concerned about the health and well-being of the risk-taker, then many strategies involving behavioral change and automatic protection may be considered. Sometimes both sets of strategies may be desirable. Since many people, after due and deliberate reflection, choose to engage in self-hazardous activities, there is a presumptive reason for society not to infringe on individual choice. The coping strategies designed to protect the risk-taker are appropriate for those situations in which there are com- pelling reasons to control or reduce the self-hazardous activities of individuals. Numerous coping methods can be employed for those risks that are co-generated by, for example, producers/ employers and consumers/workers. Consider automobile

20 safety. Many countries cope with the risk of car acci- dents by adopting seat belt usage laws, a strategy aimed at consumers or occupants of cars, not the manufac- turer. In contrast, the United States government is considering requiring the installation of automatic restraint systems (e.g., passive seat belt systems or air bags) in all new cars. This illustrates the general point that, when risks are co-generated by firms and consumers/workers, society can focus coping activities on the behavior of firms, on the behavior of consumers/ workers, on both, or on neither of these risk-generating agents. The choice among various coping strategies depends on many factors, such as economic costs, per- sonal freedom, administrative and statutory feasibility, and political popularity. me United States makes dif- ferent choices than do other countries and, therefore, the broad field of cross-cultural comparisons of coping processes is an interesting and important research domain. In the case of risks generated by production exter- nalities, most coping strategies are designed to cause businesses to internalize the social costs of their pro- duction activities. From the standpoint of economic efficiency, it appears that the sale of pollution licenses or use of effluent charges can generally accomplish a reduction in pollution more cheaply than the conventional strategy of imposing regulations on performance and design standards. This view, although widely held by economists, is not generally accepted. There are those who feel that economic disincentives will not accomplish meaningful reductions in pollution. Increased experimentation with economic approaches might provide sufficient evidence to judge whether these con- cepts can he effectively employed on a large scale. However, there is not even the theoretical knowledge to say whether this set of strategies is feasible for cop- ing with the growing problem of hazardous chemical wastes. Economists, policy analysts, engineers, and legal scholars are now studying this important issue. Selecting Risk-Coping Strategies The diversity of risk-coping strategies, including those listed in Figure 2, leads to a difficult question: What criteria should be used to select coping strategies in a

21 FIGURE 2 Strategies for Coping with Some Categories of Risks Self-Hazardous Behavior Insurance Premium Adjustments Educational Campaigns Incentives /Dis incentives Legal Restrictions Automatic Protection Strategies Liability Rules Co-Generated Risks Occupational Risks Wage Premiums for Risky Jobs Worker Compensation Programs Liability Rules Union Bargaining Informational Approaches Taxing Occupational Risks Employee Protective Measures Standard Setting for Health and Safety Consumer Product Risks Product Safety Research and Development Regulation of Advertising Product Labels and Warnings Consumption Goals and Guidelines Liability Rules Regulating Standards and Bans Risks From Production Externalities Government Standard Setting Sale of Pollution Licenses Effluent Fees Liability Rules Governmental Compensation Programs Negotiation Processes Compulsory Liability Insurance

22 - given situation? Generic rules or formulas are inappli- cable because the nature of risks differs, the ratio- nales for nocial intervention differ, and the conse- quences of various coping strategies differ. The committee can only suggest several themes that might illuminate the strategy-selection process. The first theme is that while all strategies for coping with risks--individual, market, legislative, regulatory, and judicial--have strengths, they also have serious and systematic defects. The task is to define those combinations of risk-coping strategies that can offer the flexibility and effectiveness necessary to , respond to risks. Most strategies for coping with risks are not mutually exclusive. Occupational injury taxes can complement selective safety standards by providing incentives for firms to reduce the full range of causes of injury. Meanwhile, the regulatory approach can par- tially compensate for the tort-liability system's ina- bility to disentangle multiple causes of risks involving toxic substances, especially for health risks that occur only after long latency periods. A more sophisticated understanding of the strengths and weaknesses of differ- ent coping methods can help society develop creative combinations of such methods. Society must be concerned not only with risk reduc- tion and risk prevention but also with compensating those who suffer losses as a result of certain imposed and co-generated risks. In recent decades the tort- liabilitv svatem for compensating those who have suf _ ~, ~ ~ , , , ~ fered has been adapted to the consequences of new risks, e.~.. pollution from factories affecting people, nearby farms, etc. Compensation is designed both to discourage risk-generating conduct and to provide relief to those who suffer losses from imposed and co-generated risks. Effective and equitable compensation is needed for two reasons: First, some risks are the inevitable result of public- or private-sector activities that are vital to achieving societal goals, such as a police force to maintain local safety and a military force to maintain national security. Second, some imposed and co- generated risks that should be reduced or eliminated will inevitably persist due to imperfections in regula- tion, society's lack of knowledge of appropriate methods of risk reduction, and the insensitivity of people in businesses, government agencies, legislatures, and other institutions. Third, some risks might be so costly to eliminate entirely that it may be more prudent to invest

23 resources elsewhere. For these reasons, it is important to improve mechanisms for compensating the victims of certain kinds of risks; however, victims may not be compensated at all in nonnegligent accidents, that is, those accidents in which the risk was considered too remote to be worth the cost of prevention. A second theme is the need to experiment with new or modified processes for coping with risks. Coping strat- egies such as education campaigns, the sale of pollution licenses, and revisions in tort law should not be adopted on an national scale without careful analysis, experimentation, evaluation, and adaptation. Yet inno- vations will rarely be adopted if decision makers and the public do not have confidence that such approaches will be effective. Needed are pilot projects or social experiments in which small-scale introduction of new coping processes, careful monitoring and evaluation of performance, and modifications of original innovations precede adoption of new methods on a large scale. his approach is sometimes used (e.g., in environmental policy), but could be used more extensively and more productively. Pilot projects are important not only for coping with persistent risks, such as smoking and air pollu- tion, but also for emerging environmental threats, such as inadequate disposal of hazardous wastes. Traditional coping strategies are ill-equipped to deal with risks posed by toxic substances in the air, food, water, homes, and workplaces and thereby emphasize the need to experiment with and learn from multiple strategies for attacking this problem. We add the caveat that it is very difficult to make social experiments truly repre- sentative of potential social policies. A third theme is that coping methods that preserve or increase free choice by individuals should be con- sidered. Sometimes informing the individual of ways to cope with particular risks is the best tactic, enabling free choice and avoiding direct constraints. Media campaigns to improve nutritional habits or to reduce smoking are examples of an information strategy. In other cases, more direct action is needed, such as banning certain food additives for their carcinogenic potential. The committee does not posit individual choice as an absolute value but rather suggests that for decisions by which individuals generate risks for themselves, there should be persuasive reasons to override the results of

24 individual decision making. Of course, when freedom is exercised by some to generate risks that are incurred by others, the case for considering social intervention is widely accepted. Finally, the mere existence of deficiencies in individual and market decision making about risks does not establish the claim that social institutions should intervene to reduce risks. Government decision making is also imperfect and costly, and governmental failures must be considered when deciding whether social inter- vention should be employed and what forms intervention should take. m e Emergence of Social Regulation Government regulation of risk generating activities is now pervasive. Serious market deficiencies originally gave rise to many regulatory policies. The regulatory network thereby created itself involves identified risks. Research arms of the Environmental Protection Agency, the Food and Drug Administration, the Consumer Product Safety Commission, and the National Institute of Occupational Safety and Bealth and of the various de- partments of the National Institutes of Health are constantly engaged in the identification of previously unknown risks that subsequently, quite appropriately, become potential targets of regulation. In this sense public concern about risk has evolved interactively with the growth of federal regulations.9 In the late 1960s and early 1970s, Congress created a set of powerful federal institutions charged with regulating the risk-generating activities of business firms. Compared with the regulatory agencies of the Progressive Era and the New Deal, the new social regula- tory agencies were quite different. While the goals of most old-style regulation often included control of com- petition and protection of infant industries, the new 9Undoubtedly, new real risks are being added over time to our society, and some old real risks are being miti- gated. It is not clear whether the total risk burden is increasing or decreasing; but the public perception of the different types of risk seems to be increasing and this has occurred in part synergistically with the growth of federal regulations.

25 regulation included such social goals as protection of health and the natural environment. The newer regula- tory agencies--such as the Environmental Protection Agency, the Occupational Safety and Bealth Administra- tion, the National Highway Traffic Safety Administra- tion, and the Consumer Product Safety Commission--were given broader jurisdictions to influence the risk- generating activities of business firms. Such broad regulatory jurisdictions exceed that of such single- industry agencies as the Interstate Commerce Commission and the Civil Aeronautics Board; rather the jurisdic- tions of agencies such as the Environmental Protection Agency or the National Institute for Occupational Safety and Health extend across the entire economy. The new regulation was also quite different from the old from a statutory viewpoint. For example, the Envi- ronmental Protection Agency generally is subject to constraints imposed by the courts, statutory deadlines, and the like. Many provisions of the new laws require risks to be either eliminated or reduced to the lowest technologically feasible levels. In addition, the new legislation often expands the role of judicial review by offering avenues for citizens and activist groups to sue and enforce legislative mandates. Even those statutes instructing the administrator to weigh risks, costs, and benefits often include directions on what minimum fac- tors should be considered in regulatory decision mak- ~ng. Several factors have contributed to the growth of regulation. me growing environmental consciousness of the nation, culminating in Earth Day in 1970, resulted in a widely supported call for stronger federal regula- tion to protect the nation's air and water. Simultane- ously there was a decline in the level of public confi- dence in business and the emergence of the public inter est movement, a significant new force in regulatory politics. Public interest groups expressed dismay about the so-called capture of the older regulatory agencies by regulated businesses (Vogel, 1980-19813. They set out to design and enforce a regulatory system that would be less susceptible to domination by those being regu- lated. By publicizing instances of the corporate creation and mismanagement of risks, public interest groups mobilized latent public support for risk reduction, thus contributing to the growth of social regulation. These and other groups affected by particular regulatory actions could and often did use

26 the administrative procedures called for by law to challenge and delay such actions.l° As the powerful new regulatory statutes began to be implemented in the 1970s, the politics of regulation continued to evolve. Arguments about the effects of regulation on prices, employment, productivity, competi- tion, and innovation have become a new force in the reg- ulatory battlefield, leading to various regulatory reform bills designed to reduce the economic burden of regulation. Presidents Ford and Carter implemented programs of regulatory analysis, and President Reagan has established the Regulatory Relief Task Force. The call for a rethinking of regulation has also been accelerated by the energy crisis and the nation's economic troubles, with more attention being paid to trade-offs between risk reduction and other national goals. Some agencies, such as the Consumer Product Safety Commission and the Occupational Safety and Bealth Administration, face sharp cutbacks in resources and authority as well as possible extinction. But there remains strong congressional support for regulation of certain risks, as evidenced by the passage of several major pieces of legislation in the late 1970s aimed at controlling toxic substances and hazardous wastes--for example, the Toxic Substances Control Act of 1976, the Resource Conservation and Recovery Act of 1976, and the so-called superfund law to clean up waste dumps, which was passed at the end of 1980. me new conservative political movement in the nation may further reduce support for social regula- tion. However, while it is probable that this movement will reorient thinking in Congress and agencies toward efficiency and cost-benefit comparisons, one should not necessarily expect mass deregulation in the risk area. Despite some increase in antiregulation sentiment among the public (Council on Environmental Quality, 1980), recent surveys indicate that the majority of the public continues to support regulations designed to protect consumers, workers, and the environment. Even if no new legislation is passed in the near future, there remains MA committee member points out that any inference that an increased level of activity by people who think of themselves as acting in the public interest is evi- dence that the public interest is in fact being repre- sented should be made in a very guarded fashion.

27 much unused regulatory authority on the books, enough to continue extensive social regulation in the 1980s. The agencies of the government, staffs of legislative committees, public interest groups, manufacturers of environmental monitoring and control equipment, the courts, and the media continue to house large numbers of people with personal, intellectual, and financial inter- ests in the vitality of social regulation. Moreover, the underlying justifications for social regulation-- market failures, environmental externalities, consumer and worker misinformation, and society's altruistic desire for safety--are not likely to decline in the 1980s. They may increase. THE ROLES OF SCIENCE AND ANALYSIS Many people in society make decisions with consequences for human health, safety, and the environment: con- sumers in the marketplace, workers in the factory, business executives, administrators of regulatory agencies, etc. In most cases, decision makers rely primarily on common sense, intuition, ordinary knowl- edge, and nonscientific analyses in making decisions about risks. It is frequently impossible to identify any single decision maker, as decisions evolve from dynamic processes of social interaction, which may range from the simple communication between a consumer and a seller to the complex bargaining between adversaries in an environmental dispute. All people participate in such interactive decision making about risks in their daily lives, even though they do not think about it as social interaction. In this section we explore how scientists and professional analysts can contribute to decision making about risks. It is easy for people, especially scientists and professional analysts, to form inflated hopes about the potential benefits from analytical or scientific contri- butions to decision making. It is therefore important to indicate why science and professional analysis cannot resolve many disputes about risk and decision making. One conceivable model of policy making about risk would emphasize the importance of expertise.ll Given . l L lone commentator remarks: The report cautions that wrapping oneself in the robes of expertise does not give

28 the scientific complexity of'many risk problems, it might be argued that ideal policy would be made by scientists and professional analysts. The committee rejects such a model of policy making as both unattain- able and incompatible with democratic principles. We do so for several reasons. First, decisions about social problems--such as those involving risks--almost always involve some con- flict of interest. Rarely can a decision be simultane- ously the best for all parties concerned. Even if all people benefit by a decision, some win more while others win less. While analysis can help identify the total benefits and costs of various policy alternatives, it cannot objectively resolve these conflicts of interest. Furthermore, policy choices cannot always be made polit- ically acceptable by compensating apparent losers. In a democracy, these imbalances between efficiency and equity are left to be sorted out in the political process. Second, some policy problems that are in principle analyzable--that is to say, would respond to an intel- lectual resolution if they could be pursued long and painstakingly enough--are not in fact analyzable because they run beyond anyone's cognitive capacities or beyond society's store of information. Again, these issues need political as well as intellectual contributions to their solution. The difficulties are enlarged by the facts that policy questions involve contributions from many different disciplines and that it is extremely difficult to blend these different perspectives in any formal way. Third, analysis can be done and is done by persons other than policy analysts or risk analysts. For exam- ple, public servants would be better off, on some kinds of issues, to conduct their own informal analysis of a risk problem--without any professional analysis--since they can draw on a fund of practical experience and can better cope with and respond to the realities of a par- ticular organization. one license to make public policy in which vital value judgments are concerned. The report should also point out that in an emotional and politically charged envi- ronment, the threat of anti-intellectualism and the con- sequent exclusion of factual analysis may result in a poorer decision-making process.

29 Fourth, professional analysis, even when it is more competent than any other method of assessment or evalu- ation, is fallible and inconclusive. How far to trust it, when to trust it, and when not, are questions that should be decided by appropriate political authorities; in a democratic society, that means the use of analysis should be subject to the control of the electorate and political officials. Finally, professional risk analysis is expensive and time-consuming. It is simply impossible to subject every important aspect of a policy decision to profes- sional analysis. There are not enough professionals to go around, nor would there be if their numbers were many times multiplied. The cost of analysis may exceed the benefits of the decision, or the issues may have to be decided before an analysis can be completed.l2 Given the inherently limited role of analysis in decision making, how can it help? The committee be- lieves that formal analyses can often be useful to decision makers at various levels of interaction by providing needed information or by helping decision makers to structure their thinking. One goal of this report is to articulate how analysis can be useful and how it can be made more useful. Some of the most useful analyses are not comurehen ~ , sive but rather are tailored to the purposes of a client with a specific problem. Such carefully targeted, selective, and incomplete studies are especially valuable because they conserve scarce scientific and 12A member of the committee points out that profes- sional risk analysis need not be expensive or time- consuming. A risk analysis can be professional and useful and still cheap and rapid. For example, the analysis of risk for occupational exposure to benzene took four working days. Tt is doubtful that more work would have changed the court's decision denying OSHA's reduction of occupational exposure to benzene permitted during a work day. The emphasis should not be on ~ro- fessionalism but on detail and precision. A risk analy- sis that leads to a risk of death of 1 in a billion years with an uncertainty of a factor of 10 is small enough that no further precision is necessary. Yet, one that leads to 1 in 50 years (the risk of automobile use) is large enough that improved precision and subdividing of the groups at risk may be worthwhile.

30 analytical resources. Efficiency in an individual consultant-client relationship is promoted when the analyst focuses on those elements of a decision that decision makers find most perplexing or for which they most want assistance. Many decision makers must do more than decide what risk coping strategy to advocate. They must often de- cide how to enlist the support of interest groups for a particular policy, how to enforce risk-coping strate- gies, how to defend policy positions in court and at legislative hearings, what new information to gather, what kinds of authority to delegate and to whom, and so forth. Tailor-made analyses, if responsive, judicious, and incisive, can help decision makers with this entire range of choices. Some analyses are conducted for multiple purposes and for multiple audiences. These analyses, which are often done in universities or research organizations or in some cases by the government, can usefully serve to raise the level of political discourse on some policy issue. Hey are often, however, not only used but misused as political weapons in the adversarial pro- cess. Hence, it is important that such analyses be reviewed by others and not be viewed as above the political battle.l3 In addition to aiding a decision maker in the . selection of an alternative within a specific range of choices, analysis can be useful in two other important but neglected ways. First, situations are frequent in which adversarial parties in, say, an environmental dispute are not in a zero-sum game (i.e., what one party wins the other loses). Analysis can help organize and lay the groundwork for bargaining between parties so that potential joint gains are actually realized. Second, analysis can sometimes lead to the design of superior policy alternatives. By better understanding the reasons why various alternatives are relatively . 3At least one committee member feels that publication in the open scientific literature allows the best pos- sible scope for peer review. Often, the risk analysis for a specific chemical is performed to meet a regula- tory deadline. However, this is no reason why the general procedure for the analysis, with examples of other chemicals, should not be properly published.

31 strong or weak in their details, creative new alterna- tives can be devised. The policy debate may not be resolved, but instead of a dispute between lackluster policy alternatives A and B. the debate could lead to a dispute between innovative and superior alternatives C and D. Moreover, analyses are not always intended to resolve well-formulated questions; sometimes the aim of analysis is to help formulate the right questions. That goal is often approached iteratively: a deeper insight into the right questions is achieved by struggling with what turn out to be the wrong questions. A preliminary back-of-the-envelope analysis about whether a formal analysis is worthwhile may often be helpful but often is not done. Such an analysis of whether or not to do analysis may quickly reach a point of diminishing returns; nevertheless, informal, prelimi- nary thinking can often indicate the potential gains that one might expect from deeper analysis. People differ sharply on the value of formal analy- sis: to some analysis is to be avoided, while to others analysis is to be embraced regardless of its cost. Both of these attitudes are misguided since the value of analysis will tend to vary widely depending on the prob- lem, the institution, and the cast of actors involved in the decision. The committee believes that a case-by- case examination of the value of analysis is more sen- sible and productive. Analysis, whenever it is done, should clearly state its basic assumptions and biases to enable users to evaluate it. Analysis, it should also be noted, sometimes can exacerbate controversy rather than relieve it, by enabling protagonists to fully understand that their interests are deeply opposed to those of others. Thus, it is not the case that more information and more knowl- edge always help resolve conflicts about risks. TWO ASPECTS OF RISK ANALYSIS: ASSESSMENT AND EVALUATION Individuals who must frequently decide between complex alternatives--doctors, business-executives, investment analysts, judges, and juries--rarely decompose their thinking into separate compartments and formalize each component task separately. They generally do not, for example, fo~.~.ally assess probability distributions of key uncertainties and systematically combine these assessments with value trade-offs. Rather, they gather

32 bits and pieces of facts and somehow synthesize them. They would be hard pressed to explain how they reached a decision, and, if forced to justify their action, their rationales may not accurately reflect their deeper in- sights. Even those decision analysts who espouse the divide-and-conquer philosophy of decomposition and Decomposition acknowledge that formal analysis requires experience and, at least initially, that it may not be better than informal musings. In a complex policy problem for which no single individual has command of all its facets, a decision maker and his or her advisers may wish to decompose the overall problem into parts and call on experts to help advise on the various facets. Decomposition has several benefits. It provides a focal structure for collating expertise on different facets of a problem. It also makes explicit the rationales in reasoning about the problem. Such explicitness, by facilitating peer review and providing insights into the problem, both elevates the quality of the risk analyses and points to needed research. Also, an assessment free of overt policy values may be useful to a wide range of decision makers, inside and outside the government. There is a decompo- sition of tasks that seems quite natural and that is extensively employed by such federal agencies as the Environmental Protection Agency, the Food and Drug Administration, and the Nuclear Regulatory Commission. This decomposition divides analysis into assessment and evaluation. Given their importance, a definition of these terms and a discussion of their interrelationship is warranted. One task of analysis is to identify the main uncer- tainties present in a given problem and to assess their magnitude. Is a given chemical carcinogenic? If so, what is its severity? How many people will be exposed? What are the potential health effects? What is the risk of a rupture of a dam, of a nuclear meltdown, of an LNG- induced fire? Uncertainties are particularly important in the categories of risk that society is now consider- ing: risks in which cause and effect are ill-defined and the rinks of new technologies. The policy maker may want not only a single estimate of the magnitudes of these risks but also some information about the range of uncertainty of these estimates. This is risk assess- ment. There are also assessments of consequences not involving risks to health and safety, such as effects on

33 productivity, people's happiness, and people' 8 confi- dence in institutions. After the various uncertainties are assessed, the policy choice may still be far from obvious. The policy maker has to consider, formally or informally, the al- ternative actions he or she might pursue, the institu- tional and political constraints, value and ideological judgments, and so on. This is risk evaluation.l4 It can be viewed as a subset of what some people call policy evaluation or policy analysis. It is difficult or unwise or sometimes impossible in some circumstances to separate assessment from evalua- tion. But even if the decomposition is useful, there must be an active, iterative interchange between those assessment and evaluation tasks. Problems arise in the linkages between the two tasks. There may be a conflict between what assessors feel comfortable reporting and what the evaluators need for their subsequent analyses. The assessors may be able to collect new information, but at a cost that the evaluator may judge dispropor- tionate to the intended use. There may be alternative ways to spend the funds, a possibility that may emerge only in an iterative exchange between assessors and evaluators. Such an exchange may also yield policy alternatives as well as a revised set of questions for the assessors to consider. If assessments of uncertainties are formalized and conducted separately from evaluation, it may be possible to tap the expertise of scientists without embroiling them in value-laden components of the problem. Further- more, assessment reports are generally made available to the scientific community for peer review, which is facilitated by the explicitness associated with a clear demarcation of tasks. It is also easier to modify and update an analysis that keeps science and values some- what separated. And, finally, assessment reports can serve many different clients who may clash on evaluative components. Value trade-offs are rarely absent from policy and decision making. They quite appropriately should and do enter into the evaluative phase of the policy process. But should they and do they enter into the assessment 14This terminology is not standard. What we refer to as assessment others call estimation or, more broadly, the compilation of the relevant empirical facts.

34 phase? All agree that value trade-offs should enter into the decision about which uncertainties to investi- gate, or in determining how much effort should be ex- pended in marshalling scientific facts, or even in the decision as to which facts are relevant. Some on the committee believe that it is important to say that, as an ideal, reports about uncertainties should not be dis- torted by consideration of value trade-offs; it is in this sense that those espousing this view talk of the desirability of value-neutral assessments of uncertain- ties. They feel that the assessment phase should ideally be buffered against consideration of values. They concede that this ideal is very difficult to achieve, especially when there are disagreements among the assessors about scientific facts (see Bazelon, 19791. All the committee members agree, however, that there are cases in which assessors of uncertainties have been influenced by their policy-linked value trade- offs. Some committee members feel that setting an ideal of value-neutral reporting of uncertainties is so unat- tainable that it distorts the analytical process. In a later section on "Some Issues in Risk Assess- ment" this report examines how and why concerns about policy value trade-offs do, in fact, distort assessments of uncertainties. To some, this examination reinforces their belief in the inappropriateness of the separation of assessment and evaluation. To others, this examina- tion indicates why practice deviates from the ideal and suggests how practice can be changed to cope with the more inappropriate intrusions of values in assessments. While it may baffle lay people, assessors often clash on "facts." They may disagree on the reliability of data. their import. ~ their interpretation, and their synthesis. Whether the issue is the biological effects of low-level radiation, the safety of food additives, the likelihood that chlorofluoromethanes diminish ozone in the stratosphere, or the health effects of different components of automobile exhaust t - - r - ~ - ~ the process of reach- ing a consensus on what is known and is useful for the evaluation components of decision making is invariably difficult and often contentious. Assessment, Evaluation, and Integration How difficult is it in fact to separate assessment from evaluation? Briefly, while the separation is rarely a

35 clean one to make, it is often attempted. A major dif- ficulty is in integrating these two components of risk analysis so that the information provided by the assess- ment phase truly facilitates policy evaluation and decision making. The difficulties of integration are many, including marshalling all of the data pertinent to given uncertainties, assigning probabilities to such ~ ~ ~ ~ ~ ~ line between facts and expert judgments about uncertainties and, if appli- cable, stating the reasons for the disagreement on where that line is drawn. Assessors may also be wary of the criticisms that they have applied personal values and biases to scien- tific judgments; and evaluators may be wary that judg- ments and estimates made in an assessment may have inappropriately considered policy trade-offs. A major issue then is not that of separating assessment from evaluation but of finding formal methods of improving the linkages between the two that both sides will be comfortable with. The assessors must remain confident that their examinations are "uncontaminated" by value judgments; and the policy makers must retain their freedom of action and their confidence that the assess uncertainties, clearly Indicating the meets provided are the consentlent Judgments of experts undiluted by considerations other than those given in their charge. A recent internal National Research Council study noted that the "studies that the National Research Council undertakes that address risk issues typically involve ambiguity in the definition of hazard, or paucity of data, or controversy as to physical, biolog- ical and social processes." Despite these difficulties, the report asserts, admittedly using a limited sample of reports, that the bulk of the reports conceived their charge quite narrowly as falling within the assessment phase as we are currently interpreting that term. me reports deal mainly with an assessment of scientific facts and uncertainties and, at least formally, do not engage in contentious policy-value trade-offs. The study of risk analysis in NRC reports also com- mented on the difficulties of synthesizing assessment data into a form sufficiently coherent for policy makers: A broad risk assessment almost always involves diverse kinds of analysis often developed by disci plines employing different assumptions, standards of

36 reliability and acceptance of uncertainty. For example, in a recent risk assessment--the one deal- ing with ozone depletion--epidemiology, dose- response extrapolation, chemical modeling and atmo- spheric modeling, were employed in sequence in order to estimate the potential increase in ultraviolet light-induced skin cancer and malignant melanomas possibly resulting from continued release of chloro- fluorocarbons. tne problems involved in compounding the uncertainties by combining theoretical simula- tion models, laboratory reactions, clinical observa- tions, and epidemiological correlations have not really been examined by the risk assessment litera- . . and are an important research task. Lure . Value Trade-Offs and Ethical Considerations in Risk Evaluation Risk reduction is not society's only goal. Many of the risks in society are worthwhile or acceptable, at least in the sense that trying to reduce them would, all things considered, make life worse. In some cases, society may choose to increase certain risks in order to attain other important goals. Certainly individuals do so. Hang gliding is risky and could be considered un- necessary, yet it is popular. There also may be compet- ing risks. Lowering one may raise another, or lowering one risk may be so costly to industry, and eventually to consumers, that other, more effective actions cannot be afforded. However, even if an action or a decision not to take an action raises the net probabilities of ad- verse consequences, it may have other, compelling bene- fits. On balance, society may choose an option that does not minimize long-term net risk. The broad range of objectives that should be weighed in deciding how to cope with a risk can be suggested by a specific example: an analyst trying to evaluate the consequences of some regulation intended to protect human health or safety. The evaluator may want to ponder various kinds of health effects, including how many people would be affected, not only in the entire population but also in sensitive groups. How much they would be affected (in terms of mortality, morbidity, pain, suffering, discomfort, and perhaps anxiety), who they are (by age, income, occupation, geographical location, etc.), and when they would be affected may

37 also be relevant. In addition, the evaluator may be concerned about the degree to which the risk was volun- tary or involuntary and about whether the effects would be scattered across the country or concentrated in some small group of people. But there are other measures to consider. The evaluator should be interested in effects on nature, economic growth, productivity, innovation, business competition, the distribution of income, public satisfaction with government, and the quality of busi- ness and personal decision making. Pconomic costs--and for whom--certainly matter, as might enforcement costs and political costs. These and other considerations such as aesthetics, due process, and international rami- fications may all be highly uncertain, subject to reas- sessment as new information is gathered, the target of wide disagreement, and stretched out over time; the evaluator might want information about this. Further- more, an evaluator might want to know how identifiable the victims are, the type of injuries to be expected, the number of people affected, and how accountable the decision maker will be as well as what the possibilities are for delay, experimentation, flexibility, and adapta- bility. There is more--this is just a partial checklist that could be greatly expanded. This list is not appropriate for all kinds of risks; quite a different list would apply, for example, to arms control. Furthermore, many decisions about risks will not contain many of the items in the checklist above. It is clear, however, that such lists will frequently be long and that some very difficult trade-offs among com- peting objectives will have to be made. Much of the disagreement today about how to cope with a variety of risks stems from uncertainty about their magnitude: how hazardous is benzene or saccharin or ionizing radiation? Extrapolations from observable to nonobservable conditions, either in dose level or from animals to humans, will probably remain conten- tious. If, however, contrary to all expectations all such scientific imprecision could be resolved, contro- versy would still abound and perhaps would be even more vehement. Instead of a heated argument about linear versus nonlinear extrapolations from high to low dose rates, the dispute might be about the role of government in a free society. A few simplified examples of some of the most per- plexing problems involving ethics and value trade-offs are sketched below.

38 Bow much of society's limited resources should be allocated to life-saving activities versus other pres- sing social concerns? If you had to make the uncomfortable choice of saving an anonymous 1-year-old's life or that of an anonymous 20-year-old or 60-year old, which would you choose? How important is the psychological well-being asso- ciated with clean air and blue skies compared with vari- ous levels of economic well-being? How should on an asthma attack suffered by a 30- year-old be compared with a bout of emphysema suffered by a 60-year-o1d? How should our society decide whether to save the lives of inhabitants of North America 100 years from now versus saving starving Sahelians now? Do we have the responsibility of maintaining ecolog- ical balances for nature's sake rather than--or in addi- tion to--for people's sake? To what extent should society be willing to impose . . . · ~ ~ _ costs and risks on a few members of society in order to benefit most members of society?l5 When should heroic measures be taken to prolong life? When should governments restrict individuals from self-hazardous behaviors? These long-standing issues of value are common in risk and decision making. While science and profes- sional analysis may contribute to a more informed debate concerning these trade-offs, they cannot resolve them; they may, however, help to define and structure those value trade-offs. This perspective is important because it highlights the limited albeit important role of science and professional analysis in resolving disputes over decisions about acceptable risk. 5A variation of this is: To what extent should society be willing to impose small costs and risks to a large number of members of society in order to greatly benefit a few members of society? There would be a large societal consensus on the answer if the above question were changed to say, imposing great costs to many that modestly benefit a few.

39 THE ROLE OF SCIENTISTS AND SCIENTIFIC INSTITUTIONS Many scientists are active in public debates about risk and decision making. As citizens they should be in- volved in the political process. Indeed, it can be argued that scientists who can understand the technical intricacies of complex problems have a special obliga- tion to speak out on controversial issues. But there is a price society pays for this openness. Passionate claims by equally eminent scientists on diametrically opposed sides of a policy debate may bewilder lay people. me media may exacerbate this problem by focusing attention on extreme opinions that are accom- panied by ringing rhetoric. It is hard, for the media and for the general public, to sort scientific judgments from what is primarily value-based or political opin- ion. In some cases scientists cloak controversial value judgments in scientific jargon, both consciously and unconsciously. As a result, the prestige of science and public confidence in science suffers. This dilemma has profound implications for science. It may affect--some say that it already has affected--funding for science, the selection of professions by college students, and the willingness of scientists to participate in the policy process. Furthermore, scientific progress may hold one of the keys to better and healthier lives for all, especially those in the disadvantaged, developing world; ironically, scientists, although meaning well, by engaging in heated debates involving unscientific value · ~ . . . · _ - Judgments may be undermining the tuture potential ot science for amelioration of the world's ills or for coping with the critical problems created by overpopula- tion, the depletion of resources, and the degradation of the environment. (Some committee members feel that the above remarks understate the gravity of the problem; others find them a bit melodramatic but worthy of re- flection.) Scientists engaged in debates about risk and deci- sion making should, whenever possible, attempt to say where their scientific expertise ends and where their personal value judgments begin. Of course, a scientist may not know where the boundary between the two falls; scientific expertise and value judgments may fuse, but an attempt should be made to disentangle the two. Of course, there may be a continuum of states of fuzziness, but an attempt should be made to communicate this fuzzi- ness. Further, scientists in public debate should, . -- .... ~ I. -

40 whenever possible, refer to credible evidence not sup- porting their views. Committees of specialists working under the aegis of prestigious scientific institutions who have been asked to perform some risk analysis have a responsibility both to the committee's client, the public, and the commit- tee's parent institution. These responsibilities are jeopardized when tasks are accepted that are inappropri- ate for the committee and its parent institution. For example, a committee of physical scientists sponsored by an engineering institute may not be the appropriate com- mittee to recommend policies for balancing concerns about health and safety risks with value trade-offs and political constraints. Some scientists on the committee may be knowledgeable about policy concerns, but if their expertise is sought and their institution's imprimatur is given on the basis of their professional expertise as physical scientists and not as policy analysts, then it may be inappropriate for them to make pronouncements that extend beyond their disciplinary expertise. Cer- tainly if they feel compelled to offer policy recommen- dations, such excursions should be clearly labeled in their report. Outside the committee, the members have the right and the duty to speak out on the issues, but the committee is not serving its parent institution, the . . . . . . Drosoer scenic community, or the public if it ex- pands its consultative role from the descriptive assess- ments of scientific phenomena to the prescriptive evalu- ations of policy choices--if that was not their assigned task.16 Committees are often specifically asked by their clients to suggest recommendations for policy choice "all things considered." Depending on the composition of the committee this may not be unreasonable, but com- mittees should be careful lest they become used and manipulated in a political process. Sometimes a good decision may result from shifting the burden of choice from a highly politically charged regulatory commission to some quasi-scientific body of experts, but the shift 16A commentator remarks: The scientific community needs to figure out ways to defend scientists who par- ticipate in these debates and then find themselves having their good faith questioned. This constitutes a significant disincentive for reputable scientists to become involved.

41 may be made at the expense of confusing the role of the parent scientific institution. Scientific institutions should and sometimes do inform a potential client that its interests (and society's broad interests) would be better served if the scope of the assignment is limited to nonprescriptive, nonevaluative scientific assessments. To talk about assessment and evaluation--their sepa- ration and integration--in risk analysis, we purposely draw sharp lines around each. ~ ~ ~^ ~ These lines are difficult to draw and members of many committees do not think deeply about these distinctions. Even if the agreed-on scope of a committee is to concentrate its attention on descriptive science, the committee may nevertheless slide into prescriptive, evaluative elements of an analysis, not as a conscious decision but as a natural consequence. Our suggestions are not stark. We are not saying, 'tDo not mix evaluation with assessment"; rather we are saying, "Be conscious of what you are doing. If evaluative components are prominent in your report, was such an emphasis intended? Has the committee been appropriately chosen for this task? Did the committee spend enough time considering the dynamics of choice, value trade-offs, and political and legal constraints before they arrived at their policy conclusions?t' These questions suggest there may be a conflict of interest between the needs of a client and the reputation of scientific institutions. A troublesome and not uncommon conflict is the degree to which political feasibility should be con- sidered in risk assessments. A committee may opt to consider an issue purely on technical and economic grounds only to have its judgments labeled as polit- ically naive; or it may indeed consider the political climate in weighing different options and be accused by its sponsor of overstepping its charge. A reasonable path between these two traps is for the assessors to clearly distinguish between judgments based on technical and economic grounds and those based on political con- siderations. That, again, is a matter of competent integration of assessment with evaluation. SOME ISSUES IN RISK ASSESSMENT There is one major source of controversy that plagues many risk assessments: How far should speculative numbers be pushed and combined? If benefits are

42 quantified, then there is the criticism that the 'Ward drives out the soft," that aesthetic, fragile values are ignored. Yet if these soft values are subjectively and numerically assessed, the resulting numbers are then subject to attack. If there is a vitrolic debate about whether some intangible benefit should be evaluated as worth $10,000 or $20,000, it may be easier to do the allegedly objective thing and leave it out altogether --i.e., to make it "zero." Critics complain about the failure of formal techniques to incorporate the intan- gible hunches and intuitions of experts; but if these hunches are incorporated by numerical scaling techniques (e.g., by subjective probabilities), then they can be easily ridiculed by skeptics. In the debate about how far to quantify, as in most long-standing debates, there are errors of two kinds in the balancing equation: A false sense of precision with numbers may give the impression that more is known than is really known; and a false sense of imprecision with- out numbers may give the impression that less is known than is really known. Risk assessments deal with uncertainties: some are based on copious amounts of relatively uncontroversial statistics (such as assessments of motor vehicle risks); others are based largely on reasoned speculation (such as assessments of the possibilities of sabotage of a nuclear power plant). In the former type of cases, nearly everyone would agree about the relevance of sta- tistics and estimates of probability. In the latter type of cases, although most people might have a hard time seeing how numbers can be used at all, a few people might want to numerically scale the judgments of ex- perts. hey would argue: We cannot ignore the problem of making assessments because decisions must be made, even if the decision is "no change." The problem is how to be appropriately precise about the state of impreci- sion. Some might paraphrase this as how to be appropri- ately imprecise about utter chaos. It is important for decision makers to know not only what is known but also what is not known.l7 70ne member of the committee points out that this is the procedure now recommended for dam failures, for which there is little theory and limited experience but a great deal of expert judgment.

43 There are numerous arguments for and against the use of numerical probabilities in risk assessments. But lurking in the background is a question: If you do not use probabilities, then what do you do and how will it respond to policy needs? Should experts, for example, report their subjective judgments about uncertainties when such judgments cannot be formally based on objec- tive data or on well-articulated theoretical models? All agree that if subjective judgments are reported, they should be clearly labeled as such and accompanied, insofar as possible, by supporting arguments. However, some would shun subjective statements in scientific documents altogether, especially the mixing of subjec- tive and objective judgments. It should be noted that our reference is not to subjectivity in value and poli- tical judgments, but to expert judgments about uncer- tainties, such as the uncertain severity of a toxic substance. In risk assessment, these philosophical debates about the very foundations of statistical inference have some profound, practical implications. In many investigations of the uncertainties of risks, the scientific facts speak for themselves without the need for expert synthesis; just marshalling and exhibiting them is sufficient advice to the policy maker. In other cases, however, the facts pull in different directions with different degrees of credi- bility, and if all this raw information were accurately and completely reported, it would overwhelm any policy maker. Policy makers may want experts to interpret and synthesize those facts, so that they can incorporate values and political concerns to arrive at a balanced decision. But synthesis cannot simply be computerized. It remains an art form, and judgments--expert judg- ments--have to be factored in. Yet ideally the policy maker wants the specialists to stick to their craft; the policy maker wants to learn what the specialists know about the scientific uncertainty and not about their value preferences or their political perceptions. The object is to communicate information from assessors to evaluators in a manner that will be useful in making policies and decisions. The synthesis of assessment information is profoundly influenced by whether these reports are cast in a subjectivist or an objectivist mode. Subjectivist reports may be more responsive to the evaluators' needs but may have a more difficult time in peer review.

44 Specialists disagree for many reasons, and some of them persist in disagreeing after they listen to each other at length. Perhaps there are communication bar- riers, or perhaps they talk in different paradigmatic languages, or perhaps they cannot articulate how they really feel, or perhaps they are distrustful of each other and are acting strategically. But disagree they often do. The question in what to do about such disagreements. A good case in point is a recent NRC report on the effects of radiation (National Research Council, 1981~. In extrapolating carcinogenic effects from high doses to low doses of radiation, the experts are divided on the appropriateness of three underlying extrapolatory models. In this case the experts can agree about what they disagree about--at least at the level of the choice of a model. The answer is not critical for all policy decisions--all models, for example, lead in some cases to the same policy con- clusion. But if not, what then? Can they agree on why they disagree about the appropriateness of the three models? Given that they disagree about fundamentals, can they agree on a compromise assessment report to give to the policy maker? How should groups report their ~ r - - -r disagreements? A proper separation and integration of assessment and evaluation can founder at this juncture. Indeed, it may be so difficult for an assessment group to agree on a synthesis that it may be necessary to fuse assessment and evaluation. Government agencies frequently ask scientific organ- izations to perform rink analyses by using the committee arrangement. If the task of the committee lies exclu- sively with risk assessment, then the membership of the committee should be structured primarily to yield a balanced portfolio of relevant scientific and methodo- logical skills rather than a balanced portfolio of policy viewpoints. This procedure would encourage open, honest, and nonadversarial interactions and discourage strategic, posturing regarding policy values. Some caveats apply to this, however. For one, the committee's membership and its capacity for calling on different sorts of experts should remain flexible as its perceived needs evolve during the study with deepening insights. In addition, as we emphasized earlier in com- menting on the difficulties of integrating assessment with evaluative components, there is a need for active, iterative interchange between the assessment committee

45 and those who will use its report in formulating poli- cies and decisions. Otherwise the committee may solve the wrong problem, grapple with issues irrelevant to the evaluator, or fail to gather the most important infonma- tion. Finally, it is not always easy in selecting com- mittee members to separate scientific competence from policy involvement; indeed, that competence may be due In part to Involvement In policy. Rigidity in selecting members purely for scientific competence may result then in a committee tilted toward one side of a policy de- bate. In that situation, corrective compromises may have to be made or the tasks of the committee modified. If these compromises are not made, then the public might, incorrectly, perceive ~ ~~ biased. the committee s report as Assessment reports commissioned by clients for the policy process are generally made public and reviewed by the scientific community. Peer reviews, whether for- mally commissioned or individually motivated, serve many functions: They may help potential users judge the calibre and integrity of the report; they partially motivate the authors of the report to be more respon- sible; they help to weed out errors; they may stimulate others to accumulate new evidence that would be relevant to any reassessment; and they focus attention on the weak links of the analysis. The peer review process is most effective when there is a clear demarcation of analytical tasks. When risk assessment and risk evaluation activities are mixed, it is especially difficult to orchestrate an organized review by appropriate specialists. Yet when risk as- sessment is conducted separately from evaluation, an elaborate and flexible review process can improve the quality of assessments and evaluations. For example, not only can there be reviews of the primary assessment report, but also, in a somewhat adversarial style, there can be reviews of the reviews. Funding agencies for risk assessments can incorporate a dynamic review pro- cess into funding decisions. It might be advisable to reserve substantial monies for peer review or possibly to fund two independent risk assessments, depending on the importance of the problem at hand. A final note. It is very hard to separate assess- ment from evaluation. And it is hard to do good risk assessments; there are not many examples of such assess- ments that blend well into the evaluation tasks. How- ever, the technique of deliberate separation is fairly

46 new. When done well, the results often repay the diffi- culties. Egregious errors are filtered out; high- quality reviews are more 1 ikely; and the overall stan- dards o f risk analyses are raised .

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