From 1940 to 1990, a 10% increase in a metropolitan area's concentration of college-educated residents was associated with a 0.8% increase in subsequent employment growth. Instrumental variables estimates support a causal relationship between college graduates and employment growth, but show no evidence of an effect of high school graduates. Using data on growth in wages, rents, and house values, I calibrate a neoclassical city growth model and find that roughly 60% of the employment growth effect of college graduates is due to enhanced productivity growth, the rest being caused by growth in the quality of life. This finding contrasts with the common argument that human capital generates employment growth in urban areas solely through changes in productivity.

Foreclosure laws govern the rights of borrowers and lenders when borrowers default on mortgages.Many states protect borrowers by imposing restrictions on the foreclosure process; these restrictions, in turn, impose large costs on lenders.Lenders may respond to these higher costs by reducing loan supply; borrowers may respond to the protections imbedded in these laws by demanding larger mortgages.I examine empirically the effect of the laws on equilibrium loan size.I exploit the rich geographic information available in the 1994 and 1995 Home Mortgage Disclosure Act data to compare mortgage applications for properties located in census tracts that border each other, yet are located in different states.Using semiparametric estimation methods, I find that defaulter-friendly foreclosure laws are correlated with a four percent to six percent decrease in loan size.This result suggests that defaulter-friendly foreclosure laws impose costs on borrowers at the time of loan origination.

Foreclosure laws govern the rights of borrowers and lenders when borrowers default on mortgages. In states with laws favoring the borrower, the supply of mortgage credit may decrease because lenders face higher costs. To examine the laws' effects, I compare approved mortgage applications in census tracts that border each other but are located in different states. Using a regression-discontinuity design and semiparametric estimation methods, I find that loan sizes are 3% to 7% smaller in defaulter-friendly states; this result suggests that defaulter-friendly laws impose material costs on borrowers at the time of loan origination.

We study the effects of a change in financial aid policy introduced by an anonymous university in 1998. Prior to that time, the university's financial aid packages for low-income students consisted of grants, loans, and campus jobs. After the change, the entire loan portion of the package for low-income students was replaced with grants. We find the program increased the likelihood of matriculation by low-income students by approximately 3 percentage points, although the effect is not statistically significant. The effect among low-income minority students was between 8 and 10 percentage points and statistically significant at the 10% level.

We study the effects of a change in financial aid policy introduced by a Northeastern university in 1998. Prior to that time, the university s financial aid packages for low income students consisted of grants, loans, and campus jobs. After the change, the entire loan portion of the package for low-income students was replaced with grants. We find the program increased the likelihood of matriculation by low-income students by about 3 percentage points, although the effect is not statistically significant. The effect among low-income minority students was about twice that size and statistically significant at the 10 percent level.

This paper compares technologies across space and time on the basis of factual and counterfactual substitution elasticities and argues that differences in estimated substitution elasticities should be decomposed into two counterfactual components. While the first component is designed to indicate how the ease of substitution is altered by varied economic circumstances, the second addresses the question of how technologies would compare under genuinely comparable situations. This argument is illustrated by the example of energy-price elasticities of capital before and after the oil crisis of the early 1970s.

Although economists have long been aware of Jensen's inequality, many econometric applications have neglected an important implication of it: under heteroskedasticity, the parameters of log-linearized models estimated by OLS lead to biased estimates of the true elasticities. We explain why this problem arises and propose an appropriate estimator. Our criticism of conventional practices and the proposed solution extend to a broad range of applications where log-linearized equations are estimated. We develop the argument using one particular illustration, the gravity equation for trade. We find significant differences between estimates obtained with the proposed estimator and those obtained with the traditional method.