"I present a model where a regulator monitors compliance with a policy by a population of individuals, some of whom repeatedly prefer to violate the policy, while others only occasionally want to experiment. I show that the regulator can use sanctions, contingent on past violations of the...

We investigate the effect of new facilities on attendance in professional baseball, basketball, and football from 1969 to 2001. We find a strong, persistent effect in baseball and basketball, and little effect in football. Size and duration estimates imply that baseball teams sell 2,500,794...

"Physical inactivity is considered a major public health problem. We analyze participation in physical activity using data from a nationally representative sample of individuals in 1998 and 2000 augmented with additional state-level data on government spending on parks and recreation. We find...