Collective efficacy is a neighborhood-level concept in which community members create a sense of agency and assume ownership for the state of their local community. This concept is one of several forms of formal and informal social control that predict the overall functioning of a community. In this book, the authors examine collective efficacy and crime in eight Miami-Dade County, Florida neighborhoods, based on data they collected from across the country and in the Miami-Dade neighborhoods themselves. They discuss findings relevant to the theory of collective efficacy itself, ramifications for its use within communities, and make recommendations for future research and for translating these results into actionable, crime prevention activities.