The vast amount of theoretical and empirical work on social capital that has inundated the social sciences, since the beginning of the nineties, can be roughly divided in to two categories. Firstly there are those writers, mainly political scientists and economists, who follow Putnam's line of reasoning and tend to see "associational membership" more as a source of social capital than as another form of it. Secondly those, mainly sociologists, who tend to treat the concept of social capital as primarily a social structural variable, which can be used to refer to social network or to the linkages between individuals and/or organizations. The later theorists, represented by writers such as Edwards and Foley (2001b), and Lin (2001a, 2001b), us...