The Effects of Labor Unions on Employment, Wages, and Days of Operation: Coal Mining in West Virginia
衡量了1897-1938年西弗吉尼亚州煤炭开采中工会对工资、就业和运营天数的影响，发现工会与非工会的工资差异远低于普遍认为的50%，就业差异可忽略，但1920年代工会矿场的运营天数比非工会矿场低约25%。
We present a framework for measuring the joint impact of labor unions on wages, employment, and days of work. Our particular application uses county level observations to measure the impact of unionism in West Virginia coal mining from 1897 to 1938. The widespread belief is that union-nonunion wage differentials in coal mining during this period were of the order of 50 percent or more. Our estimates are substantially less. We measure negligible differences in union-nonunion employment, while, in the 1920s, operating days in unionized mines were about 25 percent below those in nonunion mines.