Please use this form to submit your study for inclusion into our database. It will be checked by a member of the Innovation Growth Lab team, who may be in contact to ask for more information. Your email address * Your name * Title * The name of the study Short summary A brief description of the project's goals and its current state Abstract <p>Agricultural extension programs often train a few farmers and count on diffusion through social networks for the innovation to spread. However, if markets are imperfectly integrated, this may also inflict negative externalities. In a two-step experiment of an agronomy training program among Rwandan coffee farmers, we first randomize the concentration of trainees at the village level and then randomly select within each village. Knowledge increased, and yields were 6.7% higher for trained farmers. We find no evidence of social diffusion; instead, control households experienced negative spillovers in high treatment concentration areas, likely because of competition for a scarce input, fertilizer.</p> The full abstract of the study, if available Links https://economics.mit.edu/sites/default/files/inline-files/2023.05%20Chat_over_coffee_May23.pdf Links to any published papers and related discussions Authors * Affiliations Academic and other institutes that the authors of the study are members of Delivery partner Organisations involved in delivering the trial, if appropriate Year Year Year199419951996199719981999200020012002200320042005200620072008200920102011201220132014201520162017201820192020202120222023202420252026 Month MonthJanFebMarAprMayJunJulAugSepOctNovDec Day Day12345678910111213141516171819202122232425262728293031 Journal Journal publishing the study, if available Publication stage * Working Paper Published Ongoing Research Forthcoming Discussion Paper Research theme * Entrepreneurship Innovation Business Growth Country Country or countries where this study took place. Topics What sort of topics does the study cover? Sample attributes Hypotheses / research question Sample Trial population and sample selection Number of treatment groups Size of treatment groups Size of control group Unit of analysis Clustered? Yes No Cluster details Trial attributes Treatment description Rounds of data collection Baseline data collection and method Data collection method and data collected Evaluation Outcome variables Results Intervention costs Cost benefit ratio Reference Citation for use in academic references