Many studies find that presentation of balanced information, offering competing positions, can promote polarization and thus increase preexisting social divisions. We offer two explanations for this apparently puzzling phenomenon. The first involves what we call asymmetric Bayesianism: the same...

In many settings, human beings are boundedly rational. A distinctive and insufficiently explored legal response to bounded rationality is to attempt to "debias through law," by steering people in more rational directions. In many important domains, existing legal analyses emphasize the...

When members of deliberating groups speak with one another, their predeliberation tendencies often become exacerbated as their views become more extreme. The resulting phenomenon -- group polarization -- has been observed in many settings, and it bears on the actions of juries, administrative...

One in twelve Americans suffers from asthma and its annual costs are estimated to exceed $50 billion. Simultaneously, the root causes of the disease remain unknown. A recent hypothesis speculates that maternal vitamin D levels during pregnancy affect the probability the fetus later develops...

This study assesses the factors influencing the movement of people across health plans. We distinguish three types of cost-related transitions: adverse selection, the movement of the less healthy to more generous plans; adverse retention, the tendency for people to stay where they are when they...

For several decades now a debate has raged about policy-making by litigation. Spurred by the way in which tobacco, environmental, and other litigation has functioned as an alternative form of regulation, the debate asks whether policy-making or regulation by litigation is more or less socially...

Hurricane Katrina did massive damage because New Orleans and the Gulf Coast were not appropriately protected. Wherever natural disasters threaten, the government -- in its traditional role as public goods provider -- must decide what level of protection to provide to an area. It does so by...

Individual choice over health insurance policies may result in risk-based sorting across plans. Such adverse selection induces three types of losses: efficiency losses from individuals being allocated to the wrong plans; risk sharing losses since premium variability is increased; and losses from...

Catholic churches in Renaissance Florence supported themselves overwhelmingly from the contributions of wealthy citizens. The sale of private chapels within churches to individuals was a significant source of church funds, and facilitated a church construction boom. Chapel sales offered three...

We examine why managed care plans are less expensive than traditional indemnity insurance plans. Our database consists of the insurance experiences of over 200,000 state and local employees in Massachusetts and their families, who are insured in a single pool. Within this group, average HMO...