Social capital is a relatively new concept in the social sciences. In the last twenty or so years it has come to indicate that networks of social relationships represent a 'resource' for both the individual and society, since they provide support for the individual and facilitate collective action. Although this is not an entirely new idea, the more systematic way in which social capital captures such an intuition has created a new theoretical paradigm and helped to develop a series of innovative research programs in politics, economics, and the study of human well-being. The concept has gained currency beyond academia, extending its influence to political and policy-making circles at local, national, and international levels. It has also affected the way in which social surveys are conceived and public policies assessed. As the idea of social capital has spread, the literature about it has increased exponentially. After twenty years of rapid expansion it is time for a more considered and critical assessment of how the original concept has been adapted and refined, and how successful its application has been. The Handbook of Social Capital intends to do precisely that. It offers a state-of-the-art view of discussions about the concept of social capital and the way in which it has been applied in empirical research.The organization of the Handbook reflects this intention by focusing on conceptual development and analysis in the first part; by identifying two main areas of research in which social capital has favored the development of new and influential research programs--political participation in democratic societies, and economic development; and by exploring the more normative and policy oriented consequences of social capital. All chapters comprising the volume were specifically written for the Handbook by some of the main experts in the fields. The book provides an authoritative and innovative introduction to the study of social capital.