Joseph G. Altonji

Selection on Observed and Unobserved Variables: Assessing the Effectiveness of Catholic Schools.

In this paper we measure the effect of Catholic high school attendance on educational attainment and test scores. Because we do not have a good instrumental variable for Catholic school attendance, we develop new estimation methods based on the idea that the amount of selection on the observed explanatory variables in a model provides a guide to the amount of selection on the unobservables. We also propose an informal way to assess selectivity bias based on measuring the ratio of selection on unobservables to selection on observables that would be required if one is to attribute the entire effect of Catholic school attendance to selection bias. We use our methods to estimate the effect of attending a Catholic high school on a variety of outcomes. Our main conclusion is that Catholic high schools substantially increase the probability of graduating from high school and, more tentatively, attending college. We find little evidence of an effect on test scores.

Do Wages Rise with Job Seniority

The extent to which wages rise with the accumulation of seniority(tenure) in a firm after one controls for total labor market experience is a fundamental question about the structure of earnings. A variety of studies have found a large, positive partial effect of tenure on wages. This paper re-examines the evidence using a simple instrumental variables scheme to deal with well known estimation biases which arise from the fact that tenure is likely to be related to unobserved individual and job characteristics affecting the wage. We use the variation of tenure over a given job match as the principal instrumental variable for tenure. The variation intenure over the job, in contrast to variation in tenure across individuals and jobs, is uncorrelated by construction with the fixed individual specific and job match specific components of the error term of the wage equation. Our main findingis that the partial effect of tenure on wages is small, and that general labor market experience and job shopping in the labor market account for most wage growth over a career. The strong cross section relationship between tenure and wages is due primarily to heterogeneity bias.

Small sample bias in GMM estimation of covariance structures

We examine the small sample properties of the GMM estimator for models of covariance structures, where the technique is often referred to as the optimal minimum distance (OMD) estimator. We present a variety of Monte Carlo experiments based on simulated data and on the data used by Abowd and Card (1987, 1990) in an examination of the covariance structure of hours and earnings changes. Our main finding is that OMD is seriously biased in small samples for many distributions and in relatively large samples for poorly behaved distributions. The bias is almost always downward in absolute value. It arises because sampling errors in the second moments are correlated with sampling errors in the weighting matrix used by OMD. Furthermore, OMD usually has a larger root mean square error and median absolute error than equally weighted minimum distance (EWMD). We also propose and investigate an alternative estimator, which we call independently weighted optimal minimum distance (IWOMD). IWOMD is a split sample estimator using separate groups of observations to estimate the moments and the weights. IWOMD has identical large sample properties to the OMD estimator but is unbiased regardless of sample size. However, the Monte Carlo evidence indicates that IWOMD is usually dominated by EWMD.

Intertemporal Substitution in Labor Supply: Evidence from Micro Data

The sensitivity of the supply of labor to intertemporal variation in the wage is an important issue in macroeconomics, the analysis of social security and pensions, and the study of life-cycle patterns of work. This paper explores two approaches to the measurement of intertemporal substitution that have appeared in the literature. The first approach is to use consumption to control for wealth and unobserved expectations about future wages in the labor supply equation. The second approach is to estimate a first-difference equation for hours in which labor supply from the previous period serves as a control for wealth and wage expectations. The results indicate that intertemporal substitution elasticity for married men is positive but small.

Risk-sharing between and within families

This paper uses the Panel Study of Income Dynamics to test whether risk-sharing is complete between or within American families. The tests accommodate wide variety in the configuration and availability of family data. The test results reject inter- as well as intra-family full risk-sharing even assuming that leisure is endogenous or that leisure and consumption are nonseparable. Copyright 1996 by The Econometric Society.

An Evaluation of Instrumental Variable Strategies for Estimating the Effects of Catholic Schooling

Several previous studies have relied on religious affiliation and the proximity to Catholic schools as exogenous sources of variation for identifying the effect of Catholic schooling on a wide variety of outcomes. Using three separate approaches, we examine the validity of these instrumental variables. We find that none of the candidate instruments is a useful source of identification in currently available data sets. We also investigate the role of exclusion restrictions versus nonlinearity as the source of identification in bivariate probit models. The analysis may be useful as a template for the assessment of instrumental variables strategies in other applications.

Worker Characteristics, Job Characteristics, and the Receipt of On-the-Job Training

The authors examine the relationship between the receipt of employer-provided training and the characteristics of workers and jobs using data from the National Longitudinal Survey of the High School Class of 1972 and the Dictionary of Occupational Titles. They find that the intensity of training and the duration of training were negatively related; the incidence of training was slightly higher among women than among men, but the amount of training was higher among men; blacks received somewhat more training than whites; post-secondary education had a strong positive relationship with training; and aptitude had a positive effect on training. Training does not appear to have been affected by high school curriculum or by observable and unobservable factors specific to the individuals high school.

Labor Supply Preferences, Hours Constraints, and Hours-Wage Tradeoffs

In a labor market with tied hours-wage packages and wage dispersion for a particular type of job, constrained workers may be willing to sacrifice wage gains for better hours when changing jobs. Likewise, workers may accept jobs offering undesirable hours only if the associated wage gains are large. We investigate this issue empirically by examining whether overemployment and underemployment on the initial and new job affects the relation between hours changes and wage changes for quitters. Our results generally support the view that an individual requires compensation to work in a job that, given the individuals particular preferences, offers unattractive hours.

Testing the Response of Consumption to Income Changes with (Noisy) Panel Data

This paper tests the rational expectations lifecycle model of consumption against (1) a simple Keynesian model and (ii) the rational expectations lifecycle model with imperfect capital markets. The tests are based upon the relative responsiveness of consumption to income changes which can be predicted from past information and income changes which cannot be predicted. Since there is strong evidence that panel data contains substantial measurement error, the tests are especially constructed to allow for measurement error in the income process. They also allow for more general income processes than have been considered to date in the literature. The results reject the Keynesian model and generally support the lifecycle model, although the tests are not sufficiently precise to rule out the possibility that some households are liquidity constrained. Measurement error does have a strong influence on the relationship between consumption and income. When it is ignored our tests do not reject the Keynesian model. We show that consideration of measurement error may also reconcile differences in the results of Hall and Mishkin (1982) and Bernanke(1984). Nevertheless, our most important conclusion is that Hall and Mishkins, Bernankes, and Hayashis (198 ) qualitative finding that the vast majority of households obey the lifecycle model is not an artifact of failure to account for measurement error in the income data.

Chapter 48 Race and gender in the labor market

Abstract This chapter summarizes recent research in economics that investigates differentials by race and gender in the labor market. We start with a statistical overview of the trends in labor market outcomes by race, gender and Hispanic origin, including some simple regressions on the determinants of wages and employment. This is followed in Section 3 by an extended review of current theories about discrimination in the labor market, including recent extensions of taste-based theories, theories of occupational exclusion, and theories of statistical discrimination. Section 4 discusses empirical research that provides direct evidence of discrimination in the labor market, beyond “unexplained gaps” in wage or employment regressions. The remainder of the chapter reviews the evidence on race and gender gaps, particularly wage gaps. Section 5 reviews research on the impact of pre-market human capital differences in education and family background that differ by race and gender. Section 6 reviews the impact of differences in both the levels and the returns to experience and seniority, with discussion of the role of training and labor market search and turnover on race and gender differentials. Section 7 reviews the role of job characteristics (particularly occupational characteristics) in the gender wage gap. Section 8 reviews the smaller literature on differences in fringe benefits by gender. Section 9 is an extensive discussion of the empirical work that accounts for changes in the trends in race and gender differentials over time. Of particular interest is the new research literature that investigates the impact of widening wage inequality on race and gender wage gaps. Section 10 reviews research that relates policy changes to race and gender differentials, including anti-discrimination policy. The chapter concludes with comments about a future research agenda.