In a model of evolution driven by conflict between societies more powerful states have an advantage. When the influence of outsiders is small we show that this results in a tendency to hegemony. In a simple example in which institutions differ in their "exclusiveness" we find that these...

This paper derives optimal life cycle portfolio asset allocations as well as annuity purchases trajectories for a consumer who can select her hours of work and also her retirement age. Using a realistically-calibrated model with stochastic mortality and uncertain labor income, we extend the...

Delay functions, which vary timing of rewards but fix the money dimension, can elicit the form of discount functions with minimal assumptions. We present a general theorem that characterizes the set of discount functions and utility indices compatible with any 'regular' preference. We provide...

When choice options are complex, policy makers may seek to reduce decision making errors by making a high quality option the default. We show that this positive effect is at risk because such a policy creates incentives for decision makers to "drop out" by paying no attention to the decision and...

Dynamic defaults for recurring purchases determine what happens to consumers enrolled in a product or service who take no action at a decision point. Consumers may face automatic renewal, automatic switching, or non-purchase defaults. Privately optimal dynamic defaults depend on the...

In a seminal paper, Camerer, Babcock, Loewenstein, and Thaler (1997) find that the wage elasticity of daily hours of work New York City (NYC) taxi drivers is negative and conclude that their labor supply behavior is consistent with target earning (having reference dependent preferences). I...

We present a model of stereotypes in which a decision maker assessing a group recalls only that group's most representative or distinctive types relative to other groups. Because stereotypes highlight differences between groups, and neglect likely common types, they are especially inaccurate...

We investigate the determinants of giving in a lab-in-the-field experiment with large stakes. Study participants in urban Mozambique play dictator games where their counterpart is the closest person to them outside their household. When given the option, dictators do a large fraction of giving...

This paper develops a model of health insurance that incorporates behavioral biases. In the traditional model, people who are insured overuse low value medical care because of moral hazard. There is ample evidence, though, of a different inefficiency: people underuse high value medical care...

Obesity rates in the U.S. have doubled since 1980. Given the medical, social, and financial costs of obesity, a large percentage of Americans are attempting to lose weight at any given time but the vast majority of weight loss attempts fail. Researchers continue to search for safe and effective...