The Effects of Hours Constraints on Labor Supply Estimates

Almost all labor supply models are estimated under the assumption that workers are free to choose their hours. However, theory, casual empiricism and survey data suggest that many workers are not free to vary the hours within a job. Consequently, labor supply estimates based on actual hours of work may be biased. Using Canadian data on desired hours of work, we find that using actual hours causes labor supply estimates to be biased upwards but the bias is small.

The Impact of the Clean Air Act Amendments of 1990 on Electric Utilitiesand Coal Mines: Evidence from the Stock Market

If new environmental regulation imposes significant costs on firms, it should be detected in their stock prices. We use event study methodology to analyze whether President George H. Bush’s Clean Air Act Amendment (CAAA) proposals of June 1989, which were quite different from what had been expected, depressed stock prices in affected electricity generating and coal mining companies. We find that shares of 35 electric generating companies owning Phase I power plants did not noticeably fall in value after the Bush June 1989 announcement, nor after three other possibly relevant events during the preceding year. In fact, these shares increased in value during June and July of 1989. In contrast, stock prices of 11 of the 12 coal mining companies fell after Bush announced his proposals, while stock prices of a large majority of these coal companies fell after two of the other three events (although significance levels make these results not entirely conclusive). We argue that expected profits of electric generating companies did not fall because the regulated price of electricity was typically allowed to increase with costs. In the electricity industry, the costs of the CAAA were expected to be borne entirely by consumers in the form of higher prices.clean air, electric

Constraints on the Choice of Work Hours: Agency vs. Specific-Capital

Most models of implicit lifetime contracts imply that at any particular point in time, workers' wages and value of marginal product (VMP) will diverge. As a result, the contract will have to specify hours as well as wages, since firms will desire to prevent workers from working more when the wage is greater than VMP and from working less when the wage is less than VMP. this divergence, combined with the fact that in efficient contracts, the hours are set so that VMP equals the marginal value of leisure, implies that workers will face binding hours constraints. We show that the two major models of lifetime contracts, the agency model and the firm-specific capital model, make opposite predictions regarding the relation between work hours constraints and job tenure. We test these predictions. Our results indicate that neither model of efficient long-term contracts explains the observed pattern of hours constraints. Therefore, we briefly consider other explanations.

Does Science Promote Women? Evidence from Academia 1973-2001

Many studies have shown that women are under-represented in tenured ranks in the sciences. We evaluate whether gender differences in the likelihood of obtaining a tenure track job, promotion to tenure, and promotion to full professor explain these facts using the 1973-2001 Survey of Doctorate Recipients. We find that women are less likely to take tenure track positions in science, but the gender gap is entirely explained by fertility decisions. We find that in science overall, there is no gender difference in promotion to tenure or full professor after controlling for demographic, family, employer and productivity covariates and that in many cases, there is no gender difference in promotion to tenure or full professor even without controlling for covariates. However, family characteristics have different impacts on women's and men's promotion probabilities. Single women do better at each stage than single men, although this might be due to selection. Children make it less likely that women in science will advance up the academic job ladder beyond their early post-doctorate years, while both marriage and children increase men's likelihood of advancing.

Does Employer Monopsony Power Increase Occupational Accidents? The Case of Kentucky Coal Mines

A popular argument for safety regulations is that workers accept dangerous jobs because they have "no choice," or, in other words, because they have few or no alternative employment opportunities. This argument is considered in a game-theoretic framework. Because simultaneous-entry models do not yield pure-strategy equilibria, this paper develops a sequential-entry model to analyze the effect of additional firms on occupational safety. Within the context of the particular functional specification modeled, additional firms (except for the second entrant) lower average accident rates and thus increase occupational safety, consistent with the popular argument. However, with other functional specifications, the model could yield different results. As a result, the paper continues with an empirical investigation of the effect of monopsony power for a particular labor market -- nonunionized Kentucky coal mines in the later 70s -- a labor market which is likely to be particularly susceptible to monopsony. The empirical work shows that areas with many choices of alternative employers within easy driving distance do have lower accident rates. For this labor market, at least, when more alternative choices in the same occupation are offered, average occupational safety levels increase. Policies that improve occupational mobility and the competitiveness of labor markets, therefore, may simultaneously improve occupational safety.

Women in academic economics: have we made progress?

This study uses data from Academic Analytics to examine gender differences in promotion to associate professor in economics. We found that women in economics were 15% less likely to be promoted to associate professor after controlling for cumulative publications, citations, grants and grant dollars. In contrast, we found no significant gender differences in promotion in other fields including biomedical science, physical science, political science, mathematics and statistics, and engineering. We separated the sample by the research intensity of institutions and found suggestive evidence that these results were being driven by less research-intensive institutions.Accepted manuscrip

Women in economics: Moving up or falling off the academic career ladder?

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