In order to estimate the effects of unions on worker productivity, a Cobb-Douglas production function is modified so that unionization is included as a variable. The resulting functional form is similar to that used to isolate the effect of worker quality in previous studies. Using state by two-digit SIC observations for U.S. manufacturing, unionization is found to have a substantial positive effect on output per worker. However, this result depends on two important assumptions which we cannot verify directly; attempts to relax these assumptions are not conclusive.

In high school and college, men and women take significantly different courses. Using data from the Survey of Income and Program Participation and the National Longitudinal Study class of 1972, we relate these differences in school content to sex differences in adult wages. Differences in field of highest degree account for a significant part of the male‐female wage gap among college graduates, but differences in coursework account for little of the equally large wage gap between men and women with less schooling. Among college graduates there is some evidence that the reward for taking male majors is larger for men.

Welch and Moses Abramovitz and two referees for help at various stages of our work. This survey represents a substantial revision of work originally supported by the Minimum Wage Study Commission.

Charles Brown, George Fane, James Medoff; The Income Distribution as a Pure Public Good: Comment*, The Quarterly Journal of Economics, Volume 87, Issue 2,

This article investigates error properties of survey reports of labor market variables. We use the Panel Study of Income Dynamics (PSID) Validation Study, a two-wave panel survey of workers employed by a large firm that shared its detailed payroll records. Individuals' reports of annual earnings are fairly accurate. Errors are negatively related to true earnings, reducing bias due to measurement error when earnings are used as an Independent variable. Biases are moderately larger for changes in earnings. Earnings per hour are less reliably reported than annual earnings. Biases in estimating earnings functions are relatively small, but those in labor supply functions may be important.