policy-analytic metrics. Forms of life cycle analyses that can identify and link environmental consequences of technological choice are needed. Alternative economic accounting methods that include environmental cost surrogates reflecting long-term effects and changes in inventories and quality are now being developed. These are but a few of the kinds of analytic systems employing new forms of environmental calculus that will be needed to put the concept of industrial ecology into a practical context.
Policy (Sustainability) Accounts—In a manner perhaps comparable to the use of macroeconomic accounts such as gross national product or gross domestic product in shaping macropolicy choices in most countries today, a new set of sustainability accounts might be developed. The development of such accounts is essential to clarify the idea of sustainability and to develop performance measures by which we can monitor our progress toward achieving a sustainable world. No such standards, agreed upon by more than a handful of people, exist today. Such accounts, which would comprise a much richer set of metrics than the standard economic accounts, might include the following elements:
Ecological summary, including characteristics of the production/consumer web such as total flows among sectors; materials "value in use" assessments that can assist trade-off comparisons; and others.
Environmental performance indicators, including estimates of impacts on the environment with measures of the certainty of the assessments. In all of the accounts, estimates of uncertainty are critical, particularly if the so-called precautionary principle is to become a standard part of the industrial ecological policy setting algorithm.
Technology balance sheet, indicating the maturity of existing products and processes and some measure of potential for innovation.
Infrastructure balance sheet, indicating the degree to which social and technical infrastructure is adequate to support, or can adapt to, changes.
Economic indicators, including conventional as well as environmentally enhanced measures.
Political balance sheet, including the various interests affected by the set of issues under consideration with some assessment of the distribution of power.
Strategy Mapping—This element would consist of some way of using the accounts to locate the set of issues on a policy or strategic grid. For example, Charles Perrow, in his study of complex systems (1984), developed a simple mapping process to point to social choices. He set up a matrix with catastrophic potential and cost of alternative technologies as the two axes and located technologies such as nuclear power and biotechnology on the grid. In an analogy to the precautionary principle, he selected out those technologies he considered likely to fail at some time with consequent unacceptable results. No matter what form of mapping is developed, the process will be strongly influenced by political inter-