In this paper, we use an unusually rich data set from Ghana to explore the endogenous formation of information network linkages among farmers. We propose and test a new measure of social distance that accommodates possible asymmetries in social distance. Using this improved measure, we show that social distance plays a major role in shaping network structure, but that other factors related to the inherent costs and benefits of linkage matter significantly as well. Network interlinkages appear relatively modest. We are also able to corroborate the sociological "strength of weak ties" hypothesis.