Although national governments and international agencies have committed vast sums of money to development, many projects have not only failed to improve the lives of the poor but in some cases have created additional social and economic problems. Such failures can often be traced to an inadequate understanding of the socio-cultural reality of the people most directly affected and to a lack of their participation in project planning, implementation, and evaluation. In this collection of essays, scholars and practitioners from diverse disciplines examine many of the perplexing social issues of development planning from the perspective of social impact analysis. Drawing on national, regional, and local case studies, the authors demonstrate why sociocultural factors are seldom adequately understood and discuss how they can be effectively incorporated into the planning process.