Unions and productivity growth: a meta-analytic review

The impact of unions on productivity growth has received extensive
attention from researchers in industrial relations and economics. Despite
a voluminous literature, controversy continues regarding the effect of unions on productivity growth. In this paper, meta-analysis and metaregression
analysis is used to quantify the association between unions and productivity growth and to accomplish a quantitative assessment of the empirical literature. The results indicate that the overall association between unions and productivity growth is negative, especially for the U.S. The search for moderator variables revealed that most of the variation in the published results is artificial and can be attributed to specification differences.