Ronald L. Oaxaca

Male-Female Wage Differentials in Urban Labor Markets

CULTURE, TRADITION, AND OVERT DISCRIMINATION tend to make restrictive the terms by which women may participate in the labor force. These influences combine to generate an unfavorable occupational distribution of female workers vis-a-vis male workers and to create pay differences between males and females within the same occupation. The result is a chronic earnings gap between male and female full-time, year-round workers. Unfortunately, explanations at this level of generality are mainly descriptive. It is the purpose of this paper to estimate the average extent of discrimination against female workers in the United States and to provide a quantitative assessment of the sources of male-female wage differentials.

On discrimination and the decomposition of wage differentials

Abstract In this paper we examine four alternative methods for estimating the extent of labor market discrimination. All of the methods involve the decomposition of gross (unadjusted) wage differentials into discrimination and productivity components. These methods can be expressed in a single generalized form and are shown to differ with respect to the implicity assumed nondiscriminatory, competitive wage structure. Equivalencies among the methods are shown to exist under certain restrictive conditions. These methods are applied to micro data from the U.S. Current Population Survey and from a specific U.S. firm.

Identification in Detailed Wage Decompositions

The standard wage decomposition methodology produces arbitrary results when attempting to estimate the separate contributions of sets of dummy variables to the unexplained portion of the wage decomposition: the estimates are not invariant with respect to the choice of reference groups. However, the estimated separate contributions of sets of dummy variables to the explained portion and the overall decomposition are shown not to be dependent upon the choice of left-out reference groups. A similar identification problem applies to continuous variables, although this may not be as likely to cause problems in practice.

Laboratory Experiments with a Finite-Horizon Job-Search Model

In this article we explain the essential role of controlled experiments in testing job-search models. We derive the testable implications of a finite-horizon job-search model and lay out the design of the controlled experiments that we use to test those implications. We present the results of several parametric and nonparametric tests, all conditional on the actual draws of the wage offers. Overall, we find close agreement between the predictions of the search model and observations of search duration and income for several experimental treatments.

Identification of supplier induced demand in the health care sector.

This paper explores the issues and pitfalls encountered when attempting to test empirically the hypothesis that physician, hospital, or any other input supply level induces increasing demand for health services in the strict sense of demand shift and, through that, increased demand for the input in question. Evidence is presented which suggests that an empirical test of the supplier induced demand (SID) hypothesis of the type traditionally performed may not in fact be feasible with cross-sectional aggregate data such as is usually used.

New Market Power Models and Sex Differences in Pay

In the context of certain models, it is possible to infer the elasticity of labor supply to the firm from the elasticity of the quit rate with respect to the wage. We use this strategy to estimate the elasticity of labor supply for men and women workers at a chain of grocery stores, identifying separation elasticities from differences in wages and separation rates across different job titles within the firm. We estimate that women have lower elasticities, so a Robinson‐style monopsony model can explain reasonably well the lower relative pay of women in the retail grocery industry.

Inter-industry wage differentials and the gender wage gap: An identification problem

An intuitively appealing method for estimating gender wage gaps by industry is shown to yield estimates that vary according to the arbitrary choice of left-out reference groups for non-industry categorical variables, such as race and marital status. This study uses data from the Current Population Surveys to explore alternative methods for estimating gender wage gaps by industry that are not susceptible to the identification problem. Statistical significance measures reveal when relative industry wage gap rankings are not statistically meaningful. The methodology readily extends to other contexts such as racial, union-non-union, or immigrant-native wage gaps by industry, occupational, or regional groupings.

Direct Tests of the Reservation Wage Property

This paper provides the first direct experimental tests of the reservation wages predicted by finite horizon job search models. Previous indirect tests were based on search duration and search income. The authors show that such indirect tests are weak by demonstrating that a naive rule performs essentially as well as the risk neutral model in predicting search duration. In contrast, direct tests of predicted reservation wages imply rejections of both the naive rule and the risk neutral model. The general concave model survives direct tests with reservation wage data, as does a specific (logistic) concave model. Copyright 1992 by Royal Economic Society.

Wage Differentials in the 1990s in Israel: Endowments, Discrimination, and Selectivity

The purpose of this Paper is to investigate wage structures of professional workers in the Israeli labour market, using data from the most recent 1995 Census and correcting for selectivity at the stage of entrance into the occupation. The sample of professionals is decomposed into several subsamples: men and women, and within each gender a distinction is made between Easterners (originating from Asian/African countries) and Westerners (from European/American countries of origin). Comparisons by gender and ethnicity can then be made. Characteristics (endowments) and wage structures of the four groups are presented.Wage equations include the Inverse of Mills Ratio as a regressor to correct for selection into the professional occupations. Wage differences are then examined and decomposed into three components: endowments (human capital), discrimination and selectivity. Following the methodology presented in Neuman and Oaxaca (2004), four alternative decompositions are suggested and discussed.

Fixed effects models with time invariant variables: a theoretical note

Abstract This paper demonstrates the equivalence between a consistent two-stage GLS estimator and the pooled OLS estimator of the coefficients on time invariant covariates in an unbalanced FE panel. In general the estimated standard errors differ between these two procedures.