In a recent commentary in theJournal, Fran Baum raised the question, whether social capital is “good for your health?”1While the concept of social capital has had a meteoric rise in political, economic and public health rhetoric it remains to be fully defined and understood.2 3 Despite this lack of clarity, there has been the release of government and World Bank discussion papers, the staging of theme conferences and the growing use of the terms social capital, social cohesion, and civil society—all being promoted as beacons to guide public health research and practice—even though no clear, shared definition exists about what the concepts actually mean.

In the sociological literature the domain covered by the term “social capital” has been highly elastic.3 In some instances, social capital has by definition been beneficial or “good” in some way, while in others, the idea that one group's social capital can be another group's oppression has been accepted. Social capital has been used to refer to both formal and informal reciprocal links among people in all sorts of family, friendship, business and community networks. Where social capital resides—in the persons or groups linked by these networks? in the networks themselves? in the communities within which these networks exist?—is unclear. Ironically, the discourse around social capital in the health field often has a less fully socialised perspective than classic ideas about physical and financial capital being rooted in social relations of production.4 Such under-theorised applications in health research have lead to social capital being applied as a new and more fashionable label for investigations in what used to be called the “social support” field.5 Nevertheless, social capital and social cohesion have been proposed as the most important mediators of the association between income inequality and health.6 7 …