in the percentage of young males, and increases in the rate of hourly earnings (which tend to depress the injury rate since higher wages tend to attract older, more experienced workers who would be less likely to work for lower wages).

Mendeloff found that his regression formula explained 83 percent of the variation in annual injury rate changes between 1948 and 1970 (using the pre-OSHA so-called "Z-16" statistics which were discontinued after the Occupational Safety and Health Act was passed). As a result, Mendeloff concluded that: 22/

post-1970 injury rates are not significantly lower (or higher)
than we would expect on the basis of nonregulatory factors.
Therefore, we cannot reject the conclusion that OSHA has had
no effect on the overall injury rate.

Factors in Injury Rate Changes in Specific Industries

Nevertheless, the Mendeloff study did not factor into its analysis

a number of other non-OSHA influences which would be expected to impact on injury rates. Among these are changes in productivity and changes in medical practices. Moreover, his study looked at injury rates for the economy as a whole, rather than at injury rates in specific industries. It is possible that regression analyses comparing expected with experienced accident rates in specific industries could show a positive OSHA influence particularly in two industries, manufacturing and construction.

Such an analysis would be expected to take into account a number of factors affecting injury rates in various industries. These include long-term structural changes in the industry (i.e. decline in employment in some of our higher hazard "smokestack" industries within the manufacturing sector), changes in productivity, demographic changes in the workforce as the "baby boom" generation matures, different OSHA enforcement efforts

in various industries, and the extent to which injuries are reducible in

various industries.

22/ Ibid., p. 105.

IV.

BREIF OBSERVATIONS ON ACCIDENT RATE TRENDS IN VARIOUS INDUSTRIES

In lieu of an analysis concluding whether injury rates in specific industries are lower than would be expected in the absence of OSHA, some observations follow. These observations consider changes in accident rates

after they have been adjusted for fluctuations over the business cycle by measuring injury rates from peak-to-peak. These observations also consider

long-range employment patterns and productivity growth rates, two important non-OSHA influences on injury rates.

Table 3 on the following page shows average annual rates of change in injury and fatality rates for each industry, measured peak-to-peak. The succeeding two pages graph these changes. The table shows that fatality rates declined for all industry divisions measured, and that injury rates declined for all industry divisions except agriculture, the one industry that has been for the most part exempt from OSHA enforcement activity. (About 90 percent of all farms--farms with 10 or fewer workers-have been exempt from OSHA enforcement and record-keeping activity since 1974.)

Table 4 shows average annual rates of change for employment and productivity growth. The table shows that employment has increased for all industry groups except agriculture. Generally speaking, declines in employment should have a downward effect on accident rates since the employment population would tend to be reduced to older, more experienced workers, with a few replacement workers filtering in.

Conversely, the

larger the increase in employment the larger would be expected to be the

upward pressure on accident rates in the industry group.

Finally, table 4 shows an increase in productivity growth rate for

every industry except construction.

Increasing productivity growth would

be expected to be accompanied by declining accident rates, as newer, more

automated technology would be expected to accomplish both increased safety and increased productivity.

TABLE 3. Average Annual Rates of Change in Accident Rates
Industry Divisions, Measured Peak-to-Peak, 1973-1979

Source of data: Bureau of Labor Statistics, Division of Periodic Surveys, and National Safety Council, Accident Facts, 1983, p. 28.

TABLE 4. Average Annual Rates of Change in Two non-OSHA Influences on
Accident Rates 1973-1979

The productivity growth rate listed covers only transportation, not transportation and public utilities, usually included in this industry division.

Source of productivity and employment data: Bureau of Labor Statistics,
Division of Productivity and Technology.