World War II veterans earn more than nonveterans in their cohort. We test whether the World War II veteran premium reflects nonrandom selection into the military of men with higher earnings potential. The estimation is based on the fact that from 1942 to 1947 priority for conscription was determined by date of birth. Information on individuals' dates of birth may therefore be used to construct instrumental variables for veteran status. Empirical results from the 1960, 1970, and 1980 censuses, along with two other microdata sets, support a conclusion that World War II veterans earn no more than comparable nonveterans and may well earn less.

This paper uses a new survey to contrast the wages of genetically identical twins with different schooling levels. Multiple measurements of schooling levels were also collected to assess the effect of reporting error on the estimated economic returns to schooling. The data indicate that omitted ability variables do not bias the estimated return to schooling upward, but that measurement error does bias it downward. Adjustment for measurement error indicates that an additional year of schooling increases wages by 12-16 percent, a higher estimate of the economic returns to schooling than has been previously found.

On April 1, 1992, New Jersey's minimum wage rose from $4.25 to $5.05 per hour. To evaluate the impact of the law we surveyed 410 fast-food restaurants in New Jersey and eastern Pennsylvania before and after the rise. Comparisons of employment growth at stores in New Jersey and Pennsylvania (where the minimum wage was constant) provide simple estimates of the effect of the higher minimum wage. We also compare employment changes at stores in New Jersey that were initially paying high wages (above $5) to the changes at lower-wage stores. We find no indication that the rise in the minimum wage reduced employment.

This paper uses a new survey to contrast the wages of genetically identical twins with different schooling levels. Multiple measurements of schooling levels were also collected to assess the effect of reporting error on the estimated economic returns to schooling. The data indicate that omitted ability variables do not bias the estimated return to schooling upward but that measurement error does bias it downward. Adjustment for measurement error indicates that an additional year of schooling increases wages by 12 to 16 percent, a higher estimate of the economic returns to schooling than has been previously found.