We all belong to networks. Whether in the boardroom or the barroom, human beings use networks to try to achieve their goals. But not all networks are created equal, and so access to them (or the lack thereof) can drive inequality. At the same time, the networks with which we identify most — such as friends, family and colleagues — are often not the connections that prove most decisive. Rather, as our guest today has argued, it is weak ties that frequently leave the strongest influence on the course of our lives.

Mario Small is a sociologist at Columbia University. He is the author of Unanticipated Gains: Origins of Network Inequality in Everyday Life, and his work has explored how networks shape both mobility and inequality. In this conversation with host Steven Durlauf, Small discusses core insights from his 20-plus years studying urban inequality, advice for blending quantitative and qualitative methods, and the surprisingly potent networks that emerge around New York City daycare centers.