Knowledge that Transforms

Science, are currently soliciting abstracts and papers covering applied or theoretical topics relevant to the analysis of treatment effects.Possible topics include, but are not limited to: treatment effect parameters/concepts social experiments propensity score and matching techniques control function approaches nonparametric bounds regression discontinuity approaches instrumental variables stochastic dominance, quantile regression, and other techniques used to evaluate distributional effects longitudinal methods dynamic treatment effects models measurement error, missing data, or other data issues.

External recruitment is often believed to be harmful in that it trades off the need for outside talents with the incentives of inside workers. This article shows that, even from an incentive viewpoint, external recruitment has its powerful function. Specifically, if promotion is based on relative performance, then negative activities (sabotages) are a valuable instrument for competition. This results in inefficiency of the firm. External recruitment, by reducing the marginal return of negative effort relative to that of productive effort, restores the incentives in productive activity. Even without sabotage concern, external recruitment can avoid shirking equilibrium or prevent workers’ collusion.

It is common practice to use sensible rules of thumb for cleaning data. Measurement error is often the justification for removing (trimming) or recoding (winsorizing) observations where the dependent variable has values that lie outside a specified range. We consider a general measurement error process that nests many plausible models. Analytic results demonstrate that winsorizing and trimming are solutions for a narrow class of error processes. Indeed such procedures can induce or exacerbate bias. Monte Carlo simulations and empirical results demonstrate the fragility of cleaning. Even on root mean square error criteria, we cannot find generalizable justifications for these procedures.

Relicensing requirements for professionals who move across borders are widespread. In this article, we measure the effects of occupational licensing by exploiting an immigrant physician retraining assignment rule. Instrumental variables and quantile treatment effects estimates indicate large returns to acquiring an occupational license and negative selection into licensing status. We also develop a model of optimal license acquisition that, together with the empirical results, suggests that stricter relicensing requirements may lead not only to practitioner rents but also to lower average quality of service in the market for physicians.

There is renewed interest in ways to enhance secondary education, especially among disadvantaged students. This study evaluates the short-term effects of a remedial-education program that provided additional instruction to under-performing high-school students in Israel. The program targeted 10th ntwelfth graders who needed additional help to pass the matriculation exams. Using a comparison group of schools that enrolled in the program later and implementing a differences-in-differences estimation strategy, we found that the program raised the school mean matriculation rate by 3.3 percentage points. This gain reflects mainly an effect on targeted participants and the absence of externalities on their untreated peers. The program was found to be less cost-effective than two alternative interventions based on incentives for teachers and students.

How does impatience affect job search? More impatient workers search less intensively and set a lower reservation wage. The effect on the exit rate from unemployment is unclear. In this paper we show that, if agents have exponential time preferences, the reservation wage effect dominates for sufficiently patient individuals, so increases in impatience lead to higher exit rates. The opposite is true for agents with hyperbolic time preferences: more impatient workers search less and exit unemployment later. Using two large longitudinal data sets, we find that various measures of impatience are negatively correlated with search effort and the exit rate from unemployment, and are orthogonal to reservation wages. Overall, impatience has a large effect on job search outcomes in the direction predicted by the hyperbolic discounting model.

This article develops and estimates a model of wage determination that isolates the effects of alcohol use on wages as mediated through human capital accumulation. Although generally insignificant, estimation results suggest that moderate alcohol use while in school or working has a positive effect on the returns to education or experience, and therefore on human capital accumulation, but heavier drinking reduces this gain slightly. Based on these results, alcohol use does not appear to adversely affect returns to education or work experience and therefore has no negative effect on the efficiency of education or experience in forming human capital.

The Journal of Economic Literature (JEL) regularly reviews books of interest to the economics profession. The Economic Report of the President (ERP) falls under that purview and beginning this year, the JEL will be reviewing the ERP. Toward that end, I have asked a handful of very prominent economists to review the 2005 ERP. Reviewers were chosen to reflect expertise on what I guessed would be key issues. Reviewers were given the following instructions: The ERP in principle should provide an accurate assessment of the consensus professional views of economists on any given issue, based on the research to date. Does the discussion in the ERP in fact accurately summarize what we as economists know? Reviewers were given free rein over what material they would review in the ERP but were urged to focus on their areas of particular expertise. In the reviews that follow, Joel Slemrod reviews the discussion of tax reform. Joe Farrell reviews the ERP's chapter titled “Innovation and the Information Economy.” Gordon Hanson reviews the chapters on international trade and on immigration. Robert Hall reviews the discussion of the adverse macroeconomic impact of rising oil prices while Jonathan Gruber reviews the ERP chapter titled “Expanding Individual Choice and Control.” Many thanks to the reviewers for the quick turnaround.