What is social capital and how do we measure it?

Some time ago I commented on the debate over social capital. One side features Harvard professor of public policy Robert Putnam. Putnam argues that American community is in decline and that this trend has dire consequences not just for our social lives but also for our fundamental well-being (health, wealth, etc.).

I found Putnam's work overwhelmingly persuasive, so I was surprised to hear from another side. The Institute for Social Network Analysis of the Economy criticizes Putnam's acclaimed book Bowling Alone: "This book has popularized the notion of 'social capital.' His definition is plausible, but not one that is born out by social network studies."

When I originally discussed these two points of view, I suggested that Putnam would see INSAE's perfectly valid arguments as irrelevant to his thesis. Recently I found a much better analysis of the social capital debate, written by sociologists Stephen Borgatti and Candace Jones of Boston College, and Martin Everett of the University of Greenwich.

I recommend their paper, "Network Measures of Social Capital." The authors take a step back from the various positions on "social capital" and explain that each position represents a different interpretation of the term. They create a two-fold classification system of "social capital" based on the type of actor considered (individual or group) and the focus of analysis (internal actor dynamics, or external actor competition). For each category, they summarize all "reasonable" network measures of social capital.

I find the two-fold classification system very helpful at sorting through the competing claims about social capital. The various network measures of social capital are helpful, but extremely vague. I will say more about this soon. (The Red Sox/Yankees are in extra innings and I can't split my attention any longer!)