Social capital has been defined as the resources available to individuals and groups through membership in social networks. The definition is consistent with either an individualistic approach, i.e. resources (such as information or instrumental assistance) that are accessed by individuals through their network connections; or a collective approach, e.g. the benefits accruing to members of a group - such as the ability of a community to engage in collective action - as a consequence of the existence of cohesive relationships. While research often restricts itself to a single level of analysis, the benefits (and downsides) of social capital accrue to both the individual as well as to the network to which he belongs. In the Dictionary of Epidemiology both the individual and collective levels of analysis were recognized in the definition of social capital.