H. Gregg Lewis' estimates of the relative wage effect of unionism between 1920 and 1958 are routinely cited though they have rarely been subject to scrutiny. This paper extends Lewis' data to 1980 and, in particular, we construct a series on union membership that links up with the data available in the 1970's from the Current Population Surveys. We proceed to reexamine the effects of trade unions both on relative wages and on relative manhours worked.

Two models of wage and employment determination in unionized markets are routinely exposited. According to one, wage and employment outcomes are on the firm's labor demand curve; according to the other, wages and employment are on the partie' contract curve. This paper spells out an empirical procedure that discriminates between these two models and applies this procedure to the particular case of the newspaper industry and the International Typographical Union. The labor demand curve model is inconsistent with our data, while the contract curve model comes closer to describing our observations.