This paper proposes a microfoundation for social increasing returns in human capital accumulation. The underlying mechanism is a pecuniary externality due to the interaction of ex ante investments and costly bilateral search in the labor market. It is shown that the equilibrium rate of return on the human capital of a worker is increasing in the average human capital of the workforce even though all the production functions in the economy exhibit constant returns to scale, there are no technological externalities, and all workers are competing for the same jobs.

Despite a surplus of candidates for most teaching jobs, a strong academic record does little for an applicants job prospects. This does not appear to result from lukewarm interest on the part of such applicants or choosiness about the positions they accept. Administrators' lack of interest in these candidates may reflect the weakness of competitive pressures in public education. Policies intended to improve teacher quality need to consider incentives on both the demand and supply sides of the market.

Simultaneity between prisoner populations and crime rates makes it difficult to isolate the causal effect of changes in prison populations on crime. To break that simultaneity, this paper uses prison overcrowding litigation in a state as an instrument for changes in the prison population. The resulting elasticities are two to three times greater than those of previous studies. A one-prisoner reduction is associated with an increase of fifteen Index I crimes per year. While calculations of the costs of crime are inherently uncertain, it appears that the social benefits associated with crime reduction equal or exceed the social costs of incarceration for the marginal prisoner.

In an audit study of sex discrimination in hiring, comparably matched pairs of men and women applied for jobs as waiters and waitresses at restaurants in Philadelphia. In high-price restaurants (where earnings are higher), job applications from women had an estimated probability of receiving a job offer that was lower by about 0.4, and an estimated probability of receiving an interview that was lower by about 0.35. Both estimated differentials are statistically significant. Additional evidence suggests that customer discrimination partly underlies the hiring discrimination.

“Defensive medicine” is a potentially serious social problem: if fear of liability drives health care providers to administer treatments that do not have worthwhile medical benefits, then the current liability system may generate inefficiencies much larger than the costs of compensating malpractice claimants. To obtain direct empirical evidence on this question, we analyze the effects of malpractice liability reforms using data on all elderly Medicare beneficiaries treated for serious heart disease in 1984, 1987, and 1990. We find that malpractice reforms that directly reduce provider liability pressure lead to reductions of 5 to 9 percent in medical expenditures without substantial effects on mortality or medical complications. We conclude that liability reforms can reduce defensive medical practices.

We investigate the effect of abortion access on teen birthrates using county-level panel data. Past research suggested that prohibiting abortion led to higher teen birthrates. Perhaps surprisingly, we find that more recent restrictions in abortion access, including the closing of abortion clinics and restrictions on Medicaid funding, had the opposite effect. Small declines in access were related to small declines among in-wedlock births; out-of-wedlock births were relatively unaffected. Both results are consistent with a simple model in which pregnancy is endogenous and women gain new information about the attractiveness of parenthood only after becoming pregnant.

This paper explains why developed countries impose more trade barriers on middle-income countries than on either poor or other developed countries. We use a median voter model of the choice between trade and autarky embedded within an intraindustry trade model similar to Krugman. Our main result is the derivation of conditions under which a rich country rejects trade with middle-income countries, but accepts trade with either similar or poor countries. We also show that if increased inequality lowers median wealth in the developed country, the range of countries for which free trade is rejected is enlarged.

Using a panel of 51 prices from 48 cities in the United States, we provide an upper bound estimate of the rate of convergence to purchasing power parity. We find convergence rates substantially higher than typically found in cross-country data. We investigate some potentially serious biases induced by i.i.d. measurement errors in the data, and find our estimates to be robust to these potential biases. We also present evidence that convergence occurs faster for larger price differences. Finally, we find that rates of convergence are slower for cities farther apart. However, our estimates suggest that distance alone can only account for a small portion of the much slower convergence rates across national borders.

The cost of expanding public sector health programs depends critically on the extent to which public eligibility will cover just the uninsured, or will crowd out existing private insurance coverage. We estimate the extent of crowd-out arising from the expansions of Medicaid to pregnant women and children over the 1987–1992 period. We estimate that approximately 50 percent of the increase in Medicaid coverage was associated with a reduction in private insurance coverage. This occurred largely because employees took up employer-based insurance less frequently. There is also some evidence that employers contributed less for insurance and that workers dropped coverage of dependents.

The paper suggests a new test for rent-sharing in the U. S. labor market. Using an unbalanced panel from the manufacturing sector, it shows that a rise in a sector's profitability leads after some years to an increase in the long-run level of wages in that sector. The paper controls for workers' characteristics, for industry fixed effects, and for unionism. Lester's range of wages is estimated, for rentsharing reasons alone, at approximately 24 percent of the mean wage.