This paper examines the impact of pupil mobility in urban districts like Los Angeles, where families are encouraged to switch schools due to the growth of mixed-markets of charter, magnet, and pilot schools. African American and White students are more likely to exit their schools, while overcrowding in low-income Latino neighborhoods leads to higher exit rates. Charter and magnet school students exit less. The district's commitment to relieve overcrowding leads to Latino students moving to newly built schools. The opening of new high schools reduced pupil mobility.