What really matters from the point of view of social capital and civic engagement is not merely nominal membership, but active and involved membership.
Robert D. PutnamCommunity connectedness is not just about warm fuzzy tales of civic triumph. In measurable and well-documented ways, social capital makes an enormous difference in our lives...Social capital makes us smarter, healthier, safer, richer, and better able to govern a just and stable democracy.
Robert D. PutnamA society that relies on generalized reciprocity is more efficient than a distrustful society, for the same reason that money is more efficient than barter. Trust lubricates social life. Networks of civic engagement also facilitate coordination and communication and amplify information about the trustworthiness of other individuals.
Robert D. Putnam