The authors have assembled a vast body of census data to address cutting-edge issues in entrepreneurship, immigration, urban studies, economic sociology, and social policy. In a novel research formulation, they compare the 272 largest metropolitan regions of the United States in respect to the entrepreneurship of various ethno-racial groups. Such a method permits them to vary the local economic environment and resource profiles of all major categories. Virtually all previously available data on these issues relied upon averages and overlooked inter-local variation within and among groups. Interpreting the voluminous data, which summarize the economic behavior of 100 million people, Ivan Light and Carolyn Rosenstein first explain resources theory (a supply-side formulation), providing a complete review of the large theoretical literature on immigrant and ethnic entrepreneurship. They then address the other major theoretical concerns in the existing literature of social science, among them the interactionist theory of entrepreneurship and the possible effect of disadvantage upon entrepreneurship. The latter issue, an important and long-standing one, receives careful and decisive examination that eventuates in a theoretically elegant solution. A final chapter discusses social policy. The authors contrast liberal and conservative assumptions about entrepreneurship, faulting both. Locating entrepreneurship outside the usual framework of manpower policy, the authors make a case for a supply-side policy science of entrepreneurship that is neutral in political implication. Light and Rosenstein then suggest how policy might proceed to integrate two generations of social science research. Their closing discussion relates policy implications to the economic development of inner cities in America.