"Who controls corporations?" is perhaps one of the central questions of power structure research. Ralph M. Faris seeks to answer that question and more specifically "Who controls Delaware Valley corporations?" through a sustained study of the formal ties between corporations commonly referred to as "interlocks." Corporate Networks and Corporate Control provides empirical evidence of the nature and extent of interlocking directorates among Fortune 500 and Fortune 50 ranked corporations within that area. Faris generates a profile of nationally and locally oriented multiple interlockers to compare with current sociological descriptions of the national ruling class and identifies forty-eight multiple-interlockers along with data on their connections to policy-setting groups, sociocultural organizations, and religious denominations. This scaled-down but more descriptive version of a larger national study of Fortune 500 companies takes a comprehensive look at the affiliations of Philadelphia's corporate network including memberships in elite private clubs, policy-setting groups, and more. Tables and figures make the interlocking connections particularly accessible. In early chapters, Faris gives one of the clearest expositions of three different theoretical models of corporate control--Managerialism (and its more recent version, Resource Dependency), Class Cohesion, and Finance Control--and explains their distinct patterns of interlocking. Subsequent chapters give a complete picture of the methodologies of interlock analysis, including previous methods and approaches, and present a clear rendering of the facts of data collection and the geographical focus. The last two chapters examineclosely the Delaware Valley's corporate network and multiple interlocks in the context of power structure research using the actual data base of interlocking directorates in the Delaware Valley to measure the accuracy of the three models in predicting their respective patterns. This top-notch investigation makes an outstanding contribution to the fields of Economics and Economic History and will be a source of authoritative information for courses in political sociology, political economy, introductory economics, and power structure analysis in political science.