After two decades of intensive work by social scientists, the processes of economic, social, and political development of the so-called underdeveloped countries – in Latin America, Asia, and Africa – remain poorly understood. Theories that were attractive because of their simplicity and because they had clear-cut and hopeful policy implications have been badly battered by academic critics; worse, they have been faulted by events. Nevertheless, it is not true to say that we have learned nothing from the experience of the past twenty years. It’s just that what we have learned is not quite what we expected to learn….