Knowledge that Transforms

Understanding when and how individuals think about real-life problems is a central question in economics. This paper studies the role of inertia (inattention), state dependence, and learning. The empirical setting is a tariff experiment, when optional measured tariffs for local telephone calls were introduced unanticipatedly. We find that consumers tend to align their choices of tariff and telephone use levels correctly. Despite low potential savings, mistakes are not permanent, as individuals actively engage in tariff switching in order to reduce the monthly cost of telephone service. Ignoring unobservable heterogeneity and the endogeneity of past choices would have reversed these results.

There is much interest in ambiguity-averse behavior under uncertainty, and many theories have been advanced to explain this. Empirical analyses of choices involving ambiguous options have typically used a representative agent model. We address the question of whether representative agent models are accurate approximations of reality or whether there is substantial heterogeneity in ambiguity preferences. In contrast to the representative agent model, we find that the vast majority of participants are not significantly ambiguity averse and that a significant proportion of participants are consistent with expected utility theory. This finding has important implications for the application of behavioral economics.

This paper provides a method to infer the presence of treatment spillovers within markets where a fraction of agents is treated. We model individual outcomes as functions of the assigned treatment status and the distribution of assigned treatments in a market. We develop a two-step identification and estimation method, focusing first on the treatment distribution among individuals within markets and then on the treatment distribution across markets. We apply our approach to training programs for unemployed individuals in France using rich administrative data. Our results provide evidence of interactions within local labor markets as potential individual outcomes vary with the proportion of treated individuals.

This paper examines the effect of waterborne lead exposure on infant mortality in American cities over the period 1900 to 1920. Variation across cities in water acidity and the types of service pipes, which together determined the extent of lead exposure, identifies the effects of lead on infant mortality. In 1900, a decline in exposure equivalent to an increase in pH from 6.675 (25th percentile) to 7.3 (50th percentile) in cities with lead-only pipes would have been associated with a decrease in infant mortality of 7% to 33%, or at least twelve fewer infant deaths per 1,000 live births.

Empirical studies of peer effects rely on the assumption that peer spillovers can be measured through observables. However, in the education context, many theories of peer spillovers center around unobservables, such as ability, effort, or motivation. I show that when peer effects arise from unobservables, the typical empirical specifications will not measure these effects accurately, which may help explain differences in the magnitude and even sign of peer effect estimates across studies. I also show that under reasonable assumptions, these estimates cannot be applied to determine the effects of regrouping students, a central motivation of the literature.

We model the decision to travel across an international border as a trade-off between benefits derived from buying a range of products at lower prices and the costs of travel. We estimate the model using microdata on Canada–United States travel. Price differences motivate cross-border travel; a 10% home appreciation raises the propensity to cross by 8% to 26%. The larger elasticity arises when the home currency is strong, a result predicted by the model. Distance to the border strongly inhibits crossings, with an implied cost of 87 cents per mile. Geographic differences can partially explain why American travel is less exchange rate responsive.

Given the wide use of child care subsidies across countries, it is surprising how little we know about the effect of these subsidies on children's longer-run outcomes. Using a sharp discontinuity in the price of child care in Norway, we are able to isolate the effects of child care subsidies on both parental and student outcomes. We find very small and statistically insignificant effects of child care subsidies on child care utilization and parental labor force participation. Despite this, we find significant positive effect of the subsidies on children's academic performance in junior high school, suggesting that the positive shock to disposable income provided by the subsidies may be helping to improve children's scholastic aptitude.

Health insurance affects the rate at which individuals visit hospitals and emergency departments (EDs). We identify the causal effect of losing health insurance using a regression discontinuity design. We compare individuals just before and after their twenty third birthday, which insurers have used as a cutoff after which students are no longer eligible for their parents' health insurance: 1.5% of young adults lose their health insurance upon turning 23, and this transition leads to a 1.6% decrease in ED visits and a 0.8% decrease in hospital stays. We discuss why these estimates are larger than those observed among teenage populations.

This paper extends Brock and Durlauf's (2001a, 2001b) binary choice complete network (or group interaction) model with homogeneous rational expectations to a general network model with heterogeneous rational expectations. In our model, individuals will form expectations regarding peers' behaviors taking into account their characteristics. Endogenous, contextual, and correlated effects are all identifiable. Conditions for unique equilibrium are established. For a complete network with heterogeneous rational expectations, multiple equilibria can be characterized by an aggregate scalar index. The empirical results on adolescents' smoking behaviors show significant endogenous and contextual effects, even after controlling for school-grade random effects and school fixed effects.

This paper provides direct evidence on the extent of monopsony power in the low-wage labor market by estimating the firm-level elasticity of labor supply for nurse aides in the long-term care (nursing home) industry. Using exogenous variation in hiring induced by the passage of a state minimum nurse staffing law, I find that facilities initially out of compliance with the new law did not have to raise their wage offers relative to their competitors in order to hire more nurses. While this is consistent with perfect competition in simple monopsony models of the labor market, I discuss how the results may be more ambiguous in more complicated models.