Market productivity is often greater, and leisure and other household activities more enjoyable, when people perform them simultaneously. Beyond pointing out the positive externalities of synchronicity, economists have not attempted to identify exogenous causes that affect timing. We develop a...

Monitoring by peers is often an effective means of attenuating incentive problems. Most explanations of the efficacy of mutual monitoring rely either on small group size or on a version of the Folk theorem with repeated interactions which requires reasonably accurate public information...

Volunteering plays a prominent role in the charitable provision of goods and services, yet we know relatively little about why people engage in such prosocial acts. The list of possible motivations is long, but recent research has focused on altruism, reputational concerns, and material...

We examine motivations for prosocial behavior using new data on volunteer firefighters that contain a dictator game based measure of altruism, surveyed measures of other behavioral factors, and call records that provide an objective measure of time spent volunteering. Controlling for a variety...

An important claim made for affirmative action programs has been that they need not be permanent: they can be discontinued, the argument runs, once they have transformed employers' attitudes. Proposition 209, enacted in California in 1996 and made effective the following year, represents a...

Testosterone, which induces sexual differentiation of the male fetus, is believed to transfer from males to their littermates in placental mammals. Among humans, individuals with a male twin have been found to exhibit greater masculinization of sexually dimorphic attributes relative to those...