Absence of conflict of interest.
Highlights
- The study's objective was to examine the impact of occupational safety and health enforcement on health and safety, as measured by non-repeat safety violation rates and overall safety violation rates.
- The authors used regression analysis with a panel sample of 2,965 U.S. manufacturing firms to assess occupational safety and health enforcement and subsequent safety violations. The authors used firm financial data from the COMPUSTAT database and safety violation data from OSHA’s violation database covering the period from 2000-2014.
- The study found a statistically significant negative relationship between occupational safety and health enforcement—paired with Occupational Health and Safety Assessment Series (OHSAS) 18001 certification—and subsequent non-repeat and overall safety violations.
- The quality of causal evidence presented in this report is low. This means we are not confident that the estimated effects are attributable to occupational safety and health enforcement paired with OHSAS 18001 certification; other factors are likely to have contributed.
Intervention Examined
Features of the Intervention
Enhanced occupational health and safety performance can reduce operational risks, improve product quality, and increase revenue and profitability for firms. Currently, businesses are mandated to have an occupational health and safety management system to ensure their workers’ health and safety. These management systems arise from government regulation and enforcement via inspection and fines. While government enforcement agencies play a vital role as gatekeepers of safe operations, there is mixed evidence on the effectiveness of government enforcement in improving the safety performance of firms.
Developed in 1999, Occupational Health and Safety Assessment Series (OHSAS) 18001 is one of the most popular standards used for voluntary occupational safety and health management systems. Certification in OHSAS 18001 can help firms manage risks and ensure legal compliance. The literature is unclear whether voluntary occupational safety and health management systems such as OHSAS 18001 can be well integrated with mandatory systems.
Features of the Study
The authors used regression analysis with a panel sample of U.S. manufacturing firms to assess the relationship between occupational safety and health enforcement paired with OHSAS 18001 certification and subsequent safety violations. The authors used firm financial data from the COMPUSTAT database and safety violation data from OSHA's violation database covering the period from 1999 to 2014. The authors also obtained OHSAS 18001 certification data from each firm’s official website and annual report, and from media reports.
The authors linked data from 8,953 U.S. manufacturing firms from the COMPUSTAT financial database with OSHA's violation database from 1999 to 2014. The study sample includes all U.S. manufacturing firms in the COMPUSTAT financial database that also appeared in the OSHA violation database from 1999 to 2014. The study included a total of 25,273 observations of violations from 2,965 firms in both databases.
The authors used regression analysis to examine the impact of occupational safety and health enforcement paired with OHSAS 18001 certification on subsequent non-repeat and overall safety violation rates. They measured enforcement by examining past safety violations, calculated as the total number of violations committed in all years before the focal year. The authors used ordinary least squares (OLS) regressions controlling for firm characteristics and industry, state, and year fixed effects.
Findings
Health and Safety
- The study found a statistically significant negative relationship between occupational safety and health enforcement paired with OHSAS 18001 certification and subsequent non-repeat safety violations.
- The study found a statistically significant negative relationship between occupational safety and health enforcement paired with OHSAS 18001 certification and subsequent overall safety violations.
Considerations for Interpreting the Findings
The authors include statistical controls in their regression models for pre-intervention characteristics required by the protocol, including size, state, sector, and a lagged pre-intervention measure of the outcome. However, there are likely unobserved differences between the groups. The comparison group for the analysis is defined as firms with no past safety violations. Thus, this group could include both firms that did not violate safety regulations and firms that did violate safety regulations but were not identified by OSHA. As a result, the firms in the comparison group differ from the firms in the treatment group not just in their enforcement experience but also in their preexisting propensity to maintain safety levels. The estimated differences in subsequent violations may not be caused by occupational safety and health enforcement paired with OHSAS 18001 certification but could instead reflect underlying differences in safety levels or other factors between the firms being compared. Therefore, the study is not eligible for a moderate causal evidence rating, the highest rating available for nonexperimental designs.
The study authors estimated multiple related impacts on outcomes related to health and safety: non-repeat safety violation rate and overall safety violation rate. Performing multiple statistical tests on related outcomes makes it more likely that some impacts will be found statistically significant purely by chance and not because they reflect program effectiveness. The authors did not perform statistical adjustments to account for the multiple tests, so the number of statistically significant findings in this domain is likely to be overstated
Causal Evidence Rating
Research Guidelines
Review Protocol: Living Systematic Annual Search and Review Protocol
Review Guidelines: Causal Evidence Guidelines