Identification of models of the labor market

This chapter discusses identification of common selection models of the labor market. We start with the classic Roy model and show how it can be identified with exclusion restrictions. We then extend the argument to the generalized Roy model, treatment effect models, duration models, search models, and dynamic discrete choice models. In all cases, key ingredients for identification are exclusion restrictions and support conditions.Labor market

Displacement, asymmetric information and heterogeneous human capital

In a seminal paper Gibbons and Katz (1991; GK) develop and empirically test an asymmetric information model of the labor market. The model predicts that wage losses following displacement should be larger for layoffs than for plant closings, which was borne out by data from the Displaced Workers Survey (DWS). In this paper, we take advantage of many more years of DWS data to examine how the difference in wage losses across plant closing and layoff varies with race and gender. We find that the differences between white males and the other groups are striking and complex. The "lemons" effect of layoff holds for white males as in the GK model, but not for the other three demographic groups (white females, black females, and black males). These three all experience a greater decline in earnings at plant closings than at layoffs. This results from two reinforcing effects. First, plant closings have substantially more negative effects on minorities than on whites. Second, layoffs seem to have more negative consequences for white men than the other groups. These findings suggest that the GK asymmetric information model is not sufficient to explain all of the data. We augment the model with heterogeneous human capital and show that this model can explain the findings. We also provide some additional evidence suggestive that both asymmetric information and heterogeneous human capital are important. In support of both explanations, we demonstrate that the racial and gender effects are surprisingly robust to region, industry and occupation controls. To look at the asymmetric information, we make use of the Civil Rights Act of 1991 which induced employers to lay off "protected" workers in mass layoffs rather than fire them for cause. As a result, relative to whites, a layoff would be a more negative signal for blacks after 1991 than before. If information is important, this would in turn imply that blacks experience a relatively larger loss in earnings at layoffs after 1991 than prior; and that's what we find in the data. In addition, as further evidence for heterogeneous human capital, we document for the first time in the literature that the two types of layoffs reported in the DWS data, namely layoffs due to "slack work" and "position abolished" have very different features when compared to plant closings. Finally, we simulate our model and show that it can match the data.Displaced workers ; Discrimination in employment

The Labor Required for Crop Production in Ohio

Exact date of bulletin unknown.PDF pages: 1

Semiparametric reduced form estimation of tuition subsidies

The goal of this paper is to use a semiparametric reduced form model to estimate the effects of various tuition subsidies. This approach expands on the tuition subsidy example in Ichimura and Taber (2000) in a number of dimensions. It has become common practice in the empirical literature to refer to any nonstructural empirical analysis as "reduced form." This is not the traditional sense of the phrase. A classic reduced form analysis (see e.g. Marschak, 1953) first specifies a structural model and then derives the reduced form parameters in terms of the structural parameters. While many recent studies have asserted to taking a reduced form approach, the structural parameters. While many recent studies have asserted to taking a reduced form approach, the structural model which the reduced form model should correspond is rarely specified. We explicitly specify a structural model and use the implied reduced form structure to estimate the effect of tuition subsidy policies. Specifying the underlying model has the advantage of being explicit about the assumptions that justify the analysis. This avoids Rosenzweig and Wolpin's (2000) criticism of work on natural 'natural experiments' that often leaves these conditions implicit. Our structural model is based on the model studied by Keane and Wolpin (1999). It is highly nonlinear and allows for more unobserved heterogeneity than the typical simultaneous equations framework that most previous work has used in reduced form estimation. Using hte specified structural model, we examine the assumptions discussed in Ichimura and Taber (2000) to justify reduced form estimation of the policy effects

A New Bot Fly Species (Diptera: Oestridae) From Central Texas

The bot fly Cephenemyia albina (Diptera: Oestridae) is described from a relict pine forest in east-central Texas. This species presumably lives as a parasitic larva in the throat of white-tailed deer as do its two close relatives previously reported from both Texas and the Great Lakes region (C. phobifera (Clark) and C. jellisoni Townsend). Only the adult male is currently known

Layoffs, Lemons, Race, and Gender

This paper expands on Gibbons and Katz (1991) by looking at how the difference in wage losses across plant closing and layoff varies with race and gender. We find that the differences between white males and the other groups are striking and complex. The lemons effect of layoff holds for white males as in Gibbons and Katz model, but not for the other three demographic groups (white females, black females, and black males). These three all experience a greater decline in earnings at plant closings than at layoffs. This results from two reinforcing effects. First, plant closings have substantially more negative effects on minorities than on whites. Second, layoffs seem to have more negative consequences for white men than the other groups. We also find that the relative wage losses of blacks following layoffs increased after the Civil Rights Act of 1991 which we take as suggestive of an informational effect of layoff as in Gibbons and Katz. The results are suggestive that the large losses that African Americans experience at plant closing could result from heterogeneity in taste discrimination across firms.

The Egg of \u3ci\u3eStylogaster Neglecta\u3c/i\u3e Williston (Diptera: Conopidae)

Adults of both sexes and the previously unknown eggs of the parasitoid conopid fly Stylogaster neglecta Williston are illustrated and measurements are provided, including the total clutch size and the lengths and widths of eggs from random samples

Displacement, Asymmetric Information, and Heterogeneous Human Capital

In a seminal paper, Gibbons and Katz (1991) develop and empirically test an asymmetric information model of the labor market. The model predicts that wage losses following displacement should be larger for layoffs than for plant closings, which was borne out by data from the Displaced Workers Survey (DWS). In this paper, we take advantage of many more years of DWS data to examine how the difference in wage losses across plant closings and layoffs varies with race and gender. We find that the differences between white males and the other groups are striking and complex. The “lemons effect” of layoffs holds for white males, as in the Gibbons-Katz model, but not for the other three demographic groups (white females, black females, and black males). These three all experience a greater decline in earnings at plant closings than at layoffs. This results from two reinforcing effects. First, plant closings have substantially more negative effects on minorities than on whites. Second, layoffs seem to have more negative consequences for white men than the other groups. These findings suggest that the Gibbons-Katz asymmetric information model is not sufficient to explain all of the data. We augment the model with heterogeneous human capital and show that this model can explain the findings. We also provide some additional evidence suggestive that both asymmetric information and heterogeneous human capital are important. In support of both explanations, we demonstrate that the racial and gender effects are surprisingly robust to region, industry, and occupation controls. To look at the asymmetric information, we make use of the Civil Rights Act of 1991, which induced employers to lay off “protected” workers in mass layoffs rather than fire them for cause. As a result, relative to whites, a layoff would be a more negative signal for blacks after 1991 than before. If information is important, this would in turn imply that blacks experience a relatively larger loss in earnings at layoffs after 1991 than prior; and that’s what we find in the data. In addition, as further evidence for heterogeneous human capital, we document for the first time in the literature that the two types of layoffs reported in the DWS data, namely layoffs due to “slack work” and “position abolished,” have very different features when compared to plant closings. Finally, we simulate our model and show that it can match the data.human capital, plant closings, layoffs, sex, gender, race