A quarter billion people worldwide live outside their country of nationality. Most of them are migrants, people who opt to leave their countries seeking greater opportunity. One-tenth of them, though, are refugees. They are fleeing political persecution and other acute threats: barrel bombs in Syria, razed villages in Myanmar, or political turmoil, crime, and hyperinflation in Venezuela. Most refugees go to countries neighboring their own, in part so that they can return home when circumstances change.