We review developments in research on within-country migration, focusing on internal migration in the U.S. We begin by describing approaches to modelling individuals' migration decisions and equilibrium outcomes across local areas. Next, we summarize evidence regarding the impact of migration on...

International migration is characterized by two puzzling facts: First, only a small share of the population tends to migrate although substantial and persisting income differences across countries exist. Second, net migration rates tend to cease over time despite persisting income differences....