This paper provides new estimates of the medium and long-term impacts of Head Start on the health and behavioral problems of its participants. We identify these impacts using discontinuities in the probability of participation induced by program eligibility rules. Our strategy allows us to...

This study examines the impact of publicly provided daycare for children aged 0-3 on outcomes of children and their caregivers over the course of seven years after enrollment into daycare. At the end of 2007, the city of Rio de Janeiro in Brazil used a lottery to assign children to limited...

"The probability of selection into treatment plays an important role in matching and selection models. However, this probability can often not be consistently estimated, because of choice-based sampling designs with unknown sampling weights. This note establishes that the selection and matching...

This paper compares the economic questions addressed by instrumental variables estimators with those addressed by structural approaches. We discuss Marschak's Maxim: estimators should be selected on the basis of their ability to answer well-posed economic problems with minimal assumptions. A key...