What are the economic impacts of a border wall between the United States and Mexico? We use detailed data on bilateral ows of primarily unauthorized Mexican workers to the United States to estimate how a substantial expansion of the border wall between the United States and Mexico from 2007 to...

Recorded remittances to Africa have grown dramatically over the past decade. Yet data limitations still mean relatively little is known about which migrants remit, how much they remit, and how their remitting behavior varies with gender, education, income levels, and duration abroad. This paper...

We worked with two microlenders to test impacts of randomly assigned reminders for loan repayments in the "text messaging capital of the world". We do not find strong evidence that loss versus gain framing or messaging timing matter. Messages only robustly improve repayment when they include the...

How does the interplay of geography and political-economic forces affect the shape of nations? This paper presents a quantitative framework for characterizing the equilibrium evolution of national boundaries in a world with a rich geography. The framework delivers simple equilibrium conditions...

When people can self-insure via migration, they may have less need for informal risk sharing. At the same time, informal insurance may reduce the need to migrate. To understand the joint determination of migration and risk sharing I study a dynamic model of risk sharing with limited commitment...