Radio and Technology Adoption During India's Green Revolution : Evidence from a Natural Experiment

Adoption of innovative technologies is central to improving agricultural productivity. Farmers in developing countries rely heavily on social learning in adopting new technologies. Barriers to social learning such as heterogeneity or social fragmentation can therefore limit technology adoption and consequently stunt productivity growth. Can mass communication play a role in spurring technology adoption and productivity growth particularly when there are significant barriers to social learning? To answer this question empirically, I examine how the introduction of regional farm radio broadcasts impacted the adoption of high-yielding varieties (HYVs) of rice and wheat during the Green Revolution in India. To identify the causal impact of regional farm radio broadcasts, namely, dissemination agro-climate-specific information about HYVs through radio, on the adoption of the HYVs, I exploit the staggered expansion of the regional radio stations across the country. Using an annual district-level administrative dataset from 1966 to 1978, I find that introduction of regional farm radio broadcasts led to a persistent increase in the adoption of HYVs of rice, a spatially heterogeneous technology not amenable to social learning. The impact on adoption, measured as percent of the gross cropped area under HYVs was 2.4 percentage points, which is approximately 25% of the average increase in adoption over the period and close to 0.3 standard deviations. By contrast, there was at most a transient impact on the adoption of HYVs of wheat, a spatially homogeneous technology with a lot of scope for social learning. Importantly, I find that the regional farm radio broadcasts increased rice yields by 15%, a magnitude potentially large enough to justify the investments in the expansion of the regional radio network. Overall, this paper demonstrates that mass communication can indeed play a key role in diffusing profitable agricultural innovations when there are significant barriers to social learning