This study, Schools Without Diversity: Education Management Organizations, Charter Schools, and the Demographic Stratification of the American School System, explores the hotly debated question as to whether charter schools increase or decrease school segregation. This research used a national database of schools operated by Education Management Organizations (EMO), 95% of which are charter schools. The research question was whether these EMO-operated charter schools integrate or segregate students by four key demographic characteristics: ethnic/minority classification, socioeconomic status, disabling condition and English language facility. The analysis found that, as compared with the public school district in which the charter school resided, the charter schools were substantially more segregated by race, wealth, disabling condition, and language. While charter schools have rapidly grown, the strong segregative pattern found in 2001 is virtually unchanged through 2007.