We apply recent results from the statistics literature to test for multimodality of worldwide distributions of several (unweighted and population-weighted) measures of labor productivity. Specifically, we employ Silverman (Bump) and Dip modality tests, calibrated to correct for their incorrect...

In this note we present r th order kernel density derivative estimators using canonical higher-order kernels. These canonical rescalings uncouple the choice of kernel and scale factor. This approach is useful for selection of the order of the kernel in a data-driven procedure as well as for...

This note derives the general form of the approximate mean integrated squared error for the q-variate, th-order kernel density r th derivative estimator. This formula allows for normal reference rule-of-thumb bandwidths to be derived. We give tables for some of the most common cases in the...

This paper investigates how students’ collegiate athletic participation affects their subsequent labor market success. By using newly developed techniques in nonparametric regression, it shows that on average former college athletes earn a wage premium. However, the premium is not uniform, but...

This paper uses non-parametric kernel methods to construct observation-specific elasticities of substitution for a balanced panel of 73 developed and developing countries to examine the capital-skill complementarity hypothesis. The exercise shows some support for capital-skill complementarity,...

In this paper we used the procedures developed in the Kumar and Russell (2002) growth-accounting study to examine cross-country growth during the 1990's. Using a data set comprising developed, newly industrialized, developing and transitional economies, we decomposed the growth of output per...

Following an identification strategy that allows us to largely eliminate unobserved student and teacher traits, we examine the effect of homework on math, science, English and history test scores for eighth grade students in the United States. Noting that failure to control for these effects...

Despite the solid theoretical foundation on which the gravity model of bilateral trade is based, empirical implementation requires several assumptions which do not follow directly from the underlying theory. First, unobserved trade costs are assumed to be a (log-)linear function of observables....

Keller and Levinson (2002) utilize state-level panel data on inflows of foreign direct investment along with an innovative measure of relative pollution abatement costs to assess the impact of environmental stringency on capital flows. Using standard parametric panel data models, the authors...

Utilizing parametric and nonparametric techniques, we assess the role of a heretofore relatively unexplored "input" in the educational process, homework, on academic achievement. Our results indicate that homework is an important determinant of student test scores. Relative to more standard...