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...

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...

I implement event study and difference-in-differences research designs to measure the causal effects of mandatory waiting periods for abortions, distinguishing between "one- trip" waiting periods that allow counseling and information to be provided remotely and "two-trip" waiting periods that...

I compile and disseminate novel panel data sets measuring county-level travel distances to abortion facilities and resident abortion rates. Using these data and exploiting temporal and spatial variation in distances, I implement difference-in-difference research designs measuring the causal...