The correlation between instruments and explanatory variables is a key determinant of the performance of the instrumental variables estimator. The R-squared from regressing the explanatory variable on the instrument vector is a useful measure of relevance in univariate models, but can be...

This essay reviews progress in empirical economics since Leamer's (1983) critique. Leamer highlighted the benefits of sensitivity analysis, a procedure in which researchers show how their results change with changes in specification or functional form. Sensitivity analysis has had a salutary but...

We measure the impact of individuals' looks on life satisfaction/happiness. Using five data sets, from the U.S., Canada, the U.K., and Germany, we construct beauty measures in different ways that allow placing lower bounds on the effects of beauty. Beauty raises happiness: A one...

The paper proposes an instrumental variables version of the Huber estimator as an alternative to the IV-Krasker Welsch estimator. The IV-Huber estimator is analytically and computationally much simpler than IV-Krasker Welsch. In the context of an empirical study of the importance of borrowing...

This paper documents the high level of job security protection in Latin American labor markets and analyzes its impact on employment. We show that job security policies have substantial impact on the level and the distribution of employment in Latin America. They reduce employment and promote...

Measurement of seat belt and air bag effectiveness is complicated by the fact that systematic data are collected only for crashes in which a fatality occurs. These data suffer from sample selection since seat belt and air bag usage influences survival rates which in turn determine whether a...

We consider the classic problem of estimating group treatment effects when individuals sort based on observed and unobserved characteristics that affect the outcome. Using a standard choice model, we show that controlling for group averages of observed individual characteristics potentially...

In this paper, we make a first attempt to explore the relationship between computer use and productivity in French manufacturing and services industries. We match information on computer utilization in the work place collected at the employee level in the years 1987, 1991 and 1993, with...

The empirical literature on contagion has mainly measured the propagation of shocks across countries using daily stock markets, interest rates, and exchange rates. Several methodologies have been used for this purpose, however, the properties of the data introduces important limitations on the...

Innovation was rampant in the computer industry during the late 1960s and the 1970s. Did innovation vastly extend the capabilities of computers or simply reduce the costs of doing the same thing? This question goes to the heart of whether the rate of decline in 'constant-quality' computing...