Bourdieu: ‘Social capital is the ‘the aggregate of the actual or potential resources which are linked to possession of a durable network of more or less institutionalized relationships of mutual acquaintance and recognition’ (Bourdieu 1983: 249).
Coleman: ‘Social capital is defined by its function. It is not a single entity, but a variety of different entities, having two characteristics in common: they all consist of some aspect of a social structure, and they facilitate certain actions of individuals who are within the structure’ (Coleman 1994: 302).
Putnam: ‘Whereas physical capital refers to physical objects and human capital refers to the properties of individuals, social capital refers to connections among individuals – social networks and the norms of reciprocity and trustworthiness that arise from them. In that sense social capital is closely related to what some have called “civic virtue.” The difference is that “social capital” calls attention to the fact that civic virtue is most powerful when embedded in a sense network of reciprocal social relations. A society of many virtuous but isolated individuals is not necessarily rich in social capital’ (Putnam 2000: 19).
The World Bank: ‘Social capital refers to the institutions, relationships, and norms that shape the quality and quantity of a society’s social interactions… Social capital is not just the sum of the institutions which underpin a society – it is the glue that holds them together’ (The World Bank 1999).