Introduction
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DISEASE, SECONDARY
Approximately 75% of the population in sub-Saharan Africa remains dependent on agriculture for its livelihood. Increasing productivity and income for smallholder farmers is therefore often seen as a central part of the fight against poverty and hungerRecent studies highlight the large positive effect of the diffusion of modern seed varieties on economic well-being. A 10 percentage points increase in the adoption rate of modern seed varieties is associated with a 15% increase in GDP per capita across a set of 84 low and middle-income countriesDiffusion of modern seed varieties is often also argued to contribute to forest conservationThe impact of introducing yield-enhancing technologies on deforestation in a given area is, however, theoretically ambiguous. The Borlaug hypothesis builds on the assumption that output market prices decline in reaction to supply increases. But when local prices are not highly responsive to local supply conditions (for example, because demand is elastic or exogenous determinants predominate), the impact of yield-enhancing technologies may locally lead to increases in land pressure by increasing the profitability of agriculture relative to other land usesHow these different factors interact in places of particular environmental value is an important empirical question. The question, so far, has been tackled using models and simulationsThis paper uses a randomized controlled trial (RCT) to study the causal impact of modern seed variety diffusion on deforestation of the Democratic Republic of Congo (DRC), home to the largest share of the Congo River Basin forest, the second largest tropical forest in the world. The study setting is the former Equateur province (as defined before the 2015 administrative reform, and which now comprises the smaller Équateur province, as well as the Tshuapa, Mongala, Nord-Ubangi, and Sud-Ubangi provinces), host to a substantial proportion of the country’s forest cover. We study a large government program that provided subsidies for improved seed varieties of rice (short cycle), maize (high yielding), groundnuts (high yielding), and cassava (disease resistant). These varieties result from conventional breeding based on selection and crossbreeding by the National Agricultural Study and Research Institute in DRC, in partnership with CGIAR centers, and were selected for incorporation in the government program based on their suitability for the agro-ecological conditions of Equateur. None of the varieties is based on genetic modification. Out of the 92 villages covered by our study, 60 were randomly selected for the subsidy intervention. The remaining 32 villages served as control. In the treatment villages, households were randomly chosen ahead of the agricultural season to receive vouchers for the purchase of modern seed varieties at a subsidized price. The vouchers could be used for any of five of the main local staple crops and were redeemable (within 3 months) at the stores of local seed multipliers. As these stores tend to be located in distant urban areas, 35 of the treatment villages were selected for an additional intervention: a truck offered the seeds for sale directly in the center of the village a few days after the voucher distribution. This provides the exogenous variation needed to analyze the impact of the promotion of modern seed varieties on land use decisions.Our first contribution is to provide unbiased evidence of the impact of modern seed variety use on deforestation based on a randomized control trial. We define deforestation as the partial or complete removal of woody vegetation in a forested area, and we combine remote-sensing-based data at the village level with household and plot-level survey data to measure deforestation. We show evidence of changes in land conversion decisions drawing on exogenous variation in both village and household access to modern seed varieties. We also test for labor reallocation, given the potentially important role of labor supply elasticity. To our knowledge, this is the first rigorous causal (experimental) evidence of the relationship between the promotion of modern seed varieties and deforestation in the Congo Basin forest.Our second contribution is to show the importance of distinguishing between the deforestation of primary and secondary forest. Following international definitionsThe distinction between primary and secondary forest is relevant as deforestation of primary forest has substantial implications for carbon sequestration and biodiversityIn this work, we find that modern seed variety subsidy led to an increase in the deforestation of primary forest by beneficiary households. The increase in primary forest conversion is partly offset by a decrease in secondary forest conversion. The overall impact on deforestation (when aggregating primary and secondary forest) is not statistically significant, while the promotion of modern seed varieties of legumes is associated with less deforestation than the promotion of modern cereal seed varieties. By providing separate causal estimates for primary and secondary forest, this study provides micro-empirical evidence that can help motivate and extend the literature quantifying the implications of yield improvements and agricultural land sparing on greenhouse gas emissions, carbon sequestration, and biodiversity