The Occupational Safety and Health Administration (OSHA) asserts that companies preparing Injury and Illness Prevention Programs (IIPPs) can dramatically reduce workplace injuries. A 2012 OSHA white paper estimated that employers adopting IIPPs experience a 15 to 35 percent drop in injuries, and that state policies mandating IIPPs would cut workplace injuries by 12 percent. Today dozens of U.S. states require companies to use IIPPs, offer discounted workers’ compensation premiums to companies with IIPPs, or both. Researchers compared 1982-2008 reported injury data for states with policies promoting IIPP adoption with those that did not, controlling for multiple potential confounders.