  This paper studies the role of social networks in spatial mobility across
India. Using aggregated and de-identified data from the world's largest online
social network, we (i) document new descriptive findings on the structure of
social networks and spatial mobility in India; (ii) quantify the effects of
social networks on annual migration choice; and (iii) embed these estimates in
a spatial equilibrium model to study the wage implications of increasing social
connectedness. Across millions of individuals, we find that multiple measures
of social capital are concentrated among the rich and educated and among
migrants. Across destinations, both mobility patterns and social networks are
concentrated toward richer areas. A model of migration suggests individuals are
indifferent between a 10% increase in destination wages and a 12-16% increase
in destination social networks. Accounting for networks reduces the
migration-distance relationship by 19%. In equilibrium, equalizing social
networks across locations improves average wages by 3% (24% for the bottom
wage-quartile), a larger impact than removing the marginal cost of distance. We
find evidence of an economic support mechanism, with destination economic
improvements reducing the migration-network elasticity. We also find suggestive
evidence for an emotional support mechanism from qualitative surveys among
Facebook users. Difference-in-difference estimates suggest college attendance
delivers a 20% increase in network size and diversity. Taken together, our data
suggest that - by reducing effective moving costs - increasing social
connectedness across space may have considerable economic gains.
