Homophily in social relations results from both individual preferences and selective opportunities for interaction, but how these two mechanisms interact in large, contemporary organizations is not well understood. We argue that organizational structures and geography delimit opportunities for...

The empirical evidence is that only a tiny fraction of organizations live to age 40. Why this should be is a puzzle, since when firms are doing well they have all the resources (financial, physical, and intellectual) to continue to be successful. Yet the evidence is that most organizations fail....