The declining effects of OSHA inspections on manufacturing injuries, 1979-1998

This study examines the impact of OSHA inspections on injuries in manufacturing plants. The authors use the same model and some of the same plant-level data employed by several earlier studies that found large effects of OSHA inspections on injuries for 1979-85. These new estimates indicate that an OSHA inspection imposing a penalty reduced lost-workday injuries by about 19% in 1979-85, but that this effect fell to 11% in 1987-91, and to a statistically insignificant 1% in 1992-98. The authors cannot fully explain this overall decline, which they find for nearly all subgroups they examine-by inspection type, establishment size, and industry, for example. Among other findings are that, across the years studied, inspections with penalties were more effective than those without, and the effects on injury rates were greater in smaller plants and nonunion plants than in large plants and union plants.