We exploit a volcanic “experiment" to study the costs and benefits of geographic mobility. We show that moving costs (broadly defined) are very large and labor therefore does not flow to locations where it earns the highest returns. In our experiment, a third of the houses in a town were...

We estimate peer effects for fourth graders in six European countries. The identification relies on variation across classes within schools. We argue that classes within primary schools are formed roughly randomly with respect to family background. Similar to previous studies, we find sizeable...

In the early stages of the COVID-19 pandemic, international testing efforts tended to target individuals whose symptoms and/or jobs placed them at a high presumed risk of infection. Testing regimes of this sort potentially result in a high proportion of cases going undetected. Quantifying this...

Agricultural development may support broader economic development, though agricultural expansion may also crowd-out local non-agricultural activity. On the United States Plains, areas over the Ogallala aquifer experienced windfall agricultural gains when post-WWII technologies increased farmers'...

In this paper, a structural gravity model is presented which features intra-sector heterogeneity in agricultural productivity systematically linked to land and climate characteristics. The “systematic heterogeneity” (SH) gravity model predicts that countries with similar land and climate...