Knowledge that Transforms

Research as to the size of the black-white test score gap often comes to contradictory conclusions. Recent literature has affirmed that the source of these contradictions and other controversies in education economics may be due to the fact that test scores contain only ordinal information. In this paper, I propose a normalization of test scores that is invariant to monotonic transformations. Under fairly weak assumptions, this metric has interval properties and thus solves the ordinality problem. The measure can serve as a valuable robustness check to ensure that any results are not simply statistical artifacts from the choice of scale.

Decades of campaigns have cautioned households in Bangladesh about waterborne contaminants such as arsenic. In addition to switching water sources, mothers can protect young children from contaminated water by breastfeeding longer. We exploit time series variation in whether children were born before or after a nationwide information campaign and geographic variation in exposure to arsenic. We find that mothers breast-feed children longer in response to the campaign, especially when they have less access to uncontaminated wells, and that infants are more likely to be exclusively breast-fed. We find consistent evidence of lower mortality rates and diarrheal incidence for infants.

In the past twenty years, the share of top incomes in Switzerland has risen, while exhibiting large variations. Switzerland is similar to European countries for the top 1% but closer to the United States for higher top income groups. With the synthetic control method, we close a time gap in the tax data, exploiting the fact that Swiss cantons changed their tax system at different points in time. Using social security data, which cover all top labor incomes, we document the growing importance of labor compared to capital incomes among top income earners in Switzerland.

This paper introduces a new estimator for the fixed-effects ordered logit model. The proposed method has two advantages over existing estimators. First, it estimates the differences in the cut points along with the regression coefficient, leading to provide bounds on partial effects. Second, the proposed estimator for the regression coefficient is more efficient. I use the fact that the ordered logit model with J outcomes and T observations can be converted to a binary choice logit model in (J - 1)T ways. As an empirical illustration, I examine the income-health gradient for children using the Medical Expenditure Panel Survey.

We study a field experiment at a large technology company. Employees were encouraged to submit ideas on process and product improvements. The company randomly assigned nineteen teams into treatment and control groups. Treatment team employees received rewards if their ideas were approved. Nothing changed for control team employees. Our main finding is that rewards substantially increased the quality of ideas. Rewards increased participation in the suggestion system but decreased ideas per participating employee, with no net effect on the quantity of ideas. Broader participation persisted after the reward was discontinued, suggesting habituation. We find no evidence for motivational crowding out.

We provide the first evaluation of the effect of the U.S. minimum legal drinking age (MLDA) on nonfatal injuries. Using administrative records from several states and a regression discontinuity approach, we document that inpatient hospital admissions and emergency department (ED) visits increase by 8.4 and 71.3 per 10,000 person-years, respectively, at age 21. These effects are due mainly to an increase in the rate at which young men experience accidental injuries, alcohol overdoses, and injuries inflicted by others. Our results suggest that the literature’s disproportionate focus on mortality leads to a significant underestimation of the benefits of tighter alcohol control.

We assess whether welfare reform affects earnings only through mean impacts that are constant within but vary across subgroups. This is important because researchers interested in treatment effect heterogeneity typically focus on estimating mean impacts that only vary across subgroups. Using a novel approach to simulating treatment group earnings under the constant mean impacts within subgroup model, we find this model does a poor job of capturing treatment effect heterogeneity for Connecticut's Jobs First welfare reform experiment. Notably, ignoring within-group heterogeneitywould lead one to miss evidence that treatment effects are consistent with basic labor supply theory.

Michigan’s implementation of assessment limits gives rise to a wide variation in taxable basis across comparable homes. Exploiting the fact that the resulting differences in property tax liability are temporarily inherited by new homebuyers, I estimate the degree of capitalization of these largely idiosyncratic tax differences to evaluate whether homebuyers understand the tax implications of their home purchases. Consistent with anecdotal evidence but in stark contrast to the traditional view of rational consumer behavior, I find that homebuyers are woefully inattentive to the temporary nature of their initial tax obligations, resulting in an overpayment of nearly $10,000 for the average home.

We establish methods that improve the predictions of macroeconometric models—dynamic factor models, dynamic stochastic general equilibrium models, and vector autoregressions—using a quarterly U.S. data set. We measure prediction quality with one-step-ahead probability densities assigned in real time. Two steps lead to substantial improvements: (a) the use of full Bayesian predictive distributions rather than conditioning on the posterior mode for parameters and (b) the use of an equally weighted pool.

In order to measure the effect of tax credits on private R&D investment, researchers confront the difficult problem of finding an exogenous measure of tax policy that exhibits sufficient variation to support robust identification. This paper takes a new approach based on exploiting differences in the average capital-labor ratio of R&D investment across industries and variation in the tax treatment of different expenditure types across countries and over time. The estimated short-run elasticity is 0.50 which is somewhat more than double previous estimates derived from cross-country analysis.