Shadow prices of social capital in rural India, a nonparametric approach.

•The role of social capital on production efficiency and productivity is assessed.•We focus on a sample of small cotton farms in Maharashtra, India.•Data envelopment analysis, directional derivatives and a Luenberger indicator are used.•Social capital contribution to production efficiency is on the order of 507 rupees.•Investment in social capital is found to increase productivity on the order of 12%.