Union Relative Wage Effects: A Survey of Macro Estimates
综述了34项研究中的宏观数据回归结果，指出工会覆盖率对工资的影响估计混合了工会与非工会工资差距和覆盖率效应，不应直接解读为工资差距。
This paper surveys union wage effect estimates drawn from empirical cross-section wage equations fitted to macro (aggregated) data in 34 post-1963 studies containing such equations. Each estimate is the partial derivative of the dependent wage variable (in logarithmic units) with respect to the extent-of-unionism (fraction unionized) variable in the equation. This paper shows that these estimates contain a mixture in uncertain ratio of the union/nonunion wage differential or wage gap, on the one hand, and an "extent-of-unionism" effect, on the other. Therefore the Macro estimates should not be interpreted as wage gap estimates.