We study social interactions in the initiation of sex and other risky behaviors by best friend pairs in the Add Health panel. Focusing on friends with minimal experience at the baseline interview, we estimate bivariate ordered-choice models that include both peer effects and unobserved...

We test for customer discrimination with data from more than 800 retail stores employing over 70,000 individuals matched to census data on the demographics of each store's community. While our tests detect some increase in sales when the workforce more closely resembles potential customers, the...

Despite intensive scrutiny, the effects of Medicaid expansions on the health insurance status of low-income children remain controversial. We reexamine the effects of the two largest federally mandated expansions which offered Medicaid coverage to low-income children in specific age ranges and...

Defined contribution pensions in many postsecondary institutions are funded by a combination of an employer premium and a mandatory employee premium. Individuals can also contribute to a supplemental savings account. Holding constant total compensation, standard reasoning suggests that...

Critics argue that electronic voting is vulnerable to fraud. We test whether voting technology affected electoral outcomes in the 2000 and 2004 presidential elections. We find a positive correlation between use of electronic voting and George Bush vote share. The effect could have been large...