Estimating the Direct and Indirect Effects of Improved Seed Adoption on Yields: Evidence from DNA-Fingerprinting, Crop cuts, and Self-Reporting in Ethiopia

Farmer adoption of improved crop varieties can potentially increase yields and enhance household welfare in the developing world. However, the presence of measurement errors in household surveys poses a serious challenge to estimating the true returns to adopting improved varieties. This article analyzed the impacts of three sources of measurement error caused by farmers’ misperceptions of the varieties they planted, the area they planted, and the quantities they harvested, on maize yields and input use, using the 2018/19 Ethiopia Socio-economic Survey. These data included DNA-fingerprinting of seed, GPS plot size information, and crop cuts that we compared to farmers’ self-reported estimates of these measures. Doing so allowed us to determine the degree of measurement error in the estimates of improved maize adoption. Results indicated that the measurement error in self-reported adoption of improved maize varieties attenuated their estimated yield gains by 12 percentage points on average. Furthermore, we used the relationship between self-reported and DNA-fingerprinted adoption to disaggregate how much of the yield gains from improved seeds was due to better seed genetics and how much was due to increased effort by the farmers who planted them. We found that improved seed genetics accounted for a 22 percentage point yield increase over traditional seed, and observable effort through increased input use accounted for a 15 percentage point gain for improved varieties on average. Understanding these effects has important implications for justifying the continued funding of development of improved seed varieties and their dissemination to smallholder farmers.