Book excerpt: This book analyzes migrants' labor market and political integration outcomes. It argues that assimilation trade-offs shape access to economic and political resources. Migrants who are more segregated have group mobilization resources to achieve economic and political success. Migrants who are more assimilated have fewer mobilization resources and worse economic and political outcomes. The book offers a unique perspective on why migrant groups have different integration outcomes, and provides the first systematic way of understanding why assimilation outcomes do not always match economic and political outcomes.