社会资本
His first work in the area of social capital was "Making Democracy Work: Civic Traditions in Modern Italy", a comparative study of regional governments in Italy which drew great scholarly attention for its argument that the success of democracies depends in large part on the horizontal bonds that make up social capital. Putnam writes that northern Italy's history of community, guilds, clubs, and choral societies led to greater civic involvement and greater economic prosperity. Meanwhile, the agrarian society of Southern Italy is less prosperous economically and democratically because of less social capital. Social capital, which Putnam defines as "networks and norms of civic engagement", allows members of a community to trust one another. When community members trust one another, trade, money-lending, and democracy flourish.