mine accidents per worker-hour and the decline in output per worker-hour that began in the late 1960s.
A second contributor to the productivity decline was the flare-up of traditional labor-management conflict that began in the late 1960s.53 Per worker-day, deep-mine productivity dropped from about 16 tons in 1969 to about 8 tons in 1978. Surface mine productivity dropped, in the latter part of this period, from about 37 tons to about 25 tons in 1978 (see Figure 4–4).54
A third source of the productivity decline was the opening of more marginal mines in the 1970s to meet growing demand. Just as productivity was aided in the previous decade by stagnant demand and the closing of marginal mines, it was reduced by the expansion of mining, especially in the East, to more difficult seams.
The passage of the 1969 Coal Mine Health and Safety Act (amended in 1977), which set more stringent health and safety standards for mining, was a fourth source of the productivity decline. A measure of the effectiveness of the act was the 60 percent cut in the number of deaths per million hours of exposure in underground mining (and in absolute numbers from 220 in 1970 to 100 in 1977). However, an improvement in the historical rate of disabling injuries (i.e., those causing the loss of at least 1 day’s work following the day of the injury) appeared only in 1974 and 1975. The 1977 rate was 7 percent higher than the 1969 rate, and total annual injuries in underground mining remain in the 9000–11,000 range. Fatalities and disabling injuries per hour in surface mines occur about half as frequently as in underground mines; moreover, the fatality rate in surface mines has fallen to about one third of the 1970 level, and the disabling injury rate has declined about 13 percent.55
The Office of Technology Assessment (OTA) has estimated that if output rises from about 0.7 billion tons in 1977 to 1.5 billion tons in 2000 at constant labor productivity and injury rates, total annual fatalities would rise from 139 to 259 and disabling injuries would grow from 15,000 to 29,000. The estimate shows almost the entire increase in each category would occur in underground mines. To reduce injury rates further, the OTA urged that improved engineering and safety standards be extended to more aspects of mining machinery, that mine inspections be made more frequently, and that labor, industry, and government make stronger efforts at safety training, especially at mines with high accident rates.56
The 1969 act also limited the amount of respirable dust to be allowed in the mines, established enforcement procedures, and granted compensation to miners totally disabled by any of the ailments with respiratory symptoms that are collectively called “black lung.” From 1970 to 1977, 421,000 miners have received $5.6 billion in black lung compensation.57