Unions and profitability: a meta-analysis

The effect of unions on profits continues to be an unresolved empirical issue. In this paper, meta-regression analysis is applied to the population of 45 econometric studies that report 532 estimates of the direct effect of unions on profits. We show that unions have a significant negative effect on profits, and that this effect is larger in the US. Separate meta-regression analysis is used to identify the sources of union-profit effects. Meta-analysis of 239 estimates of unions interacted with the hypothesized sources of union rents reveals that neither the market power nor the quasi-rent appropriation theories are supported by the extant studies. Analysis of the between-study heterogeneity reveals that unions have an indirect effect on factor accumulation – they depress physical capital formation and stimulate advertising expenditure. There is a clear need for additional primary research in this area.