Studies of the effects of unions on collegiate faculty salaries are inconclusive. Some estimate a significant union premium, but such estimates suffer from endogeneity between unions and wages, non-random measurement error, and failure to adjust for local cost-of-living differences. By using data from the National Study of Postsecondary Faculty (NSOPF, 1988(NSOPF, -2004 as well as other sources to identify institution-specific factors omitted from previous studies, the authors estimate significantly smaller union premia than those found by other researchers.wisdom holds that collective bargaining increases the wages of unionized workers relative to their nonunion counterparts. Such wisdom has substantial theoretical and empirical support and appears to apply to both the private and public sectors.1 In the higher-education