We estimate habit formation in voting—the effect of past on current turnout—by exploit-ing transitory voting cost shocks. Using county-level data on U.S. presidential elections from 1952-2012, we find that rainfall on current and past election days reduces voter turnout. Our estimates imply that a 1-point decrease in past turnout lowers current…

The focus of this paper is the endogenous formation of peer groups. In our model, agents choose peers before making contributions to public projects, and they differ in how much they value one project relative to another. Thus, the group's preference composition affects the type of contributions made. We characterize stable groups and find that…

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…

This paper analyzes the effects of information about inequality and taxes on preferences for redistribution using randomized online surveys on Amazon Mechanical Turk (mTurk). About 5,000 respondents were randomized into treatments providing interactive information on U.S. income inequality, the link between top income tax rates and economic growth…

Ten of the 15 seats on the U.N. Security Council are held by rotating members serving two-year terms. We find that a country's U.S. aid increases by 59 percent and its U.N. aid by 8 percent when it rotates onto the council. This effect increases during years in which key diplomatic events take place (when members' votes should be especially…

Over the past 30 years, many states have abolished parole boards, which traditionally have had the discretion to release inmates before the expiration of their full sentence, in favor of fixed-sentence regimes in which the original sentence is binding. However, if prison time lowers recidivism risk and if parole boards can accurately estimate…

I develop a model in which a child's acquisition of a given form of human capital incentivizes adults in his household to either learn from him (if children act as teachers then adults' cost of learning the skill falls) or lean on him (if children's human capital substitutes for that of adults in household production then adults' benefit of…

We analyze party discipline in the House of Representatives between 1947 & 1998. The effects of party pressures can be represented in a spatial model by allowing each party to have its own cutting line on roll call votes. Adding a second cutting line makes, at best, a marginal improvement over the standard single-line model. Analysis of…