Knowledge that Transforms

To combat adverse selection, governments increasingly base payments to health plans and providers on enrollees’ scores from risk-adjustment formulae. In 2004, Medicare began to risk-adjust capitation payments to private Medicare Advantage (MA) plans to reduce selection-driven overpayments. But because the variance of medical costs increases with the predicted mean, incentivizing enrollment of individuals with higher scores can increase the scope for enrolling "overpriced" individuals with costs significantly below the formula's prediction. Indeed, after risk adjustment, MA plans enrolled individuals with higher scores but lower costs conditional on their score. We find no evidence that overpayments were on net reduced.

Do lobbyists provide issue-specific information to members of Congress? Or do they provide special interests access to politicians? We present evidence to assess the role of issue expertise versus connections in the US Federal lobbying process and illustrate how both are at work. In support of the connections view, we show that lobbyists follow politicians they were initially connected to when those politicians switch to new committee assignments. In support of the expertise view, we show that there is a group of experts that even politicians of opposite political affiliation listen to. However, we find a more consistent monetary premium for connections than expertise.

We document three remarkable features of the Opower program, in which social comparison-based home energy reports are repeatedly mailed to more than six million households nationwide. First, initial reports cause high-frequency “action and backsliding,” but these cycles attenuate over time. Second, if reports are discontinued after two years, effects are relatively persistent, decaying at 10–20 percent per year. Third, consumers are slow to habituate: they continue to respond to repeated treatment even after two years. We show that the previous conservative assumptions about post-intervention persistence had dramatically understated cost effectiveness and illustrate how empirical estimates can optimize program design.

Quantifications of gains from trade in heterogeneous firm models assume that productivity is Pareto distributed. Replacing this assumption with log-normal heterogeneity retains some useful Pareto features, while providing a substantially better fit to sales distributions-especially in the left tail. The cost of log-normal is that gains from trade depend on the method of calibrating the fixed cost and productivity distribution parameters. When set to match the size distribution of firm sales in a given market, the log-normal assumption delivers gains from trade in a symmetric two-country model that can be twice as large as under the Pareto assumption.

During the last three decades government debt has increased in most developed countries. During the same period we have also observed a significant liberalization of international financial markets. We propose a multicountry model with incomplete markets and show that governments may choose higher levels of debt when financial markets become internationally integrated. We also show that public debt increases with the volatility of uninsurable income (idiosyncratic risk). To the extent that the increase in income inequality observed in some industrialized countries has been associated with higher idiosyncratic risk, the paper suggests another potential mechanism for the rise in public debt.

Hume (1748) challenged the idea that a general claim (e.g., “all swans are white”) can be validated by empirical evidence, no matter how compelling. We examine this issue from the perspective of a tester who must accept or reject the forecasts of a potential expert. If experts can be skeptical about the validity of claims then they can evade rejection strategically. In contrast, if experts are required to conclude that claims backed by sufficient evidence are likely to be true, then they can be tested and rejected. These results provide an economic rationale for claim validation based on incentive problems.

We survey 561 students from US medical schools shortly after they submit choice rankings over residencies to the National Resident Matching Program. We elicit (i) these choice rankings, (ii) anticipated subjective well-being (SWB) rankings, and (iii) expected features of the residencies (such as prestige). We find substantial differences between choice and anticipated-SWB rankings in the implied trade-offs between residency features. In our data, evaluative SWB measures (life satisfaction and Cantril's Ladder) imply trade-offs closer to choice than does affective happiness (even time-integrated), and as close as do multimeasure SWB indices. We discuss implications for using SWB data in applied work.

Neuroeconomics strives to use knowledge from neuroscience to improve models of decisionmaking. Here we introduce a biologically plausible, drift-diffusion model that is able to jointly predict choice behavior and response times across different choice environments. The model has both normative and positive implications for economics. First, we consistently observe that decisionmakers inefficiently allocate their time to choices for which they are close to indifference. We demonstrate that we can improve subjects' welfare using a simple intervention that puts a time limit on their choices. Second, response times can be used to predict indifference points and the strength of preferences.

We study interdependencies in spousal labor supply by exploiting the design of the French workweek reduction, which introduced exogenous variation in one's spouse's labor supply, at constant earnings. Treated employees work on average two hours less per week. Husbands of treated women respond by reducing their labor supply by about half an hour, consistent with substantial leisure complementarity, and specifically cut the nonusual component of their workweek, leaving usual hours unchanged. Women's response to their husband's treatment is instead weak and rarely statistically significant, possibly due to heavier constraints in the organization of their workweek.

The endowment effect, the tendency to value possessions more than non-possessions, is a well-known departure from rational choice and has been replicated in numerous settings. We investigate the universality of the endowment effect, its evolutionary significance, and its dependence on environmental factors. We experimentally test for the endowment effect in an isolated and evolutionarily relevant population of hunter-gatherers, the Hadza Bushmen of Northern Tanzania. We find that Hadza living in isolated regions do not display the endowment effect, while Hadza living in a geographic region with increased exposure to modern society and markets do display the endowment effect.