When knowledgeable neighbors also share seedlings: diffusion of banana cultivation in Tanzania

Abstract Networks have been found to increase adoption of technology by providing information about the new technology (e.g., Conley and Udry, 2010). However, little is known about provision of necessary inputs for adoption through networks. Using data from an intervention in Tanzania, I discuss how a farmer's network can also affect the adoption of improved banana cultivation by providing seedlings. A solidarity chain principle obliged project farmers to pass on improved seedlings to other farmers free of charge. I provide a theoretical framework to guide intuition for the empirical results and suggest an empirical distinction between information and input provision through networks. Empirically, I find support for network effects through provision of both information and inputs, jointly boosting the network effect on adoption: a farmer is 39 percentage points more likely to adopt banana cultivation if there is at least one banana grower in the farmer's network compared to none. In this setting, it is not possible to fully disentangle the input and information channel. While the findings suggest that a solidarity chain principle could be an interesting avenue to boost local diffusion of new technologies, more research is needed to unpack the causal impact and the interplay with existing input markets.