Variance of log yield across farms in the United States: The 95th percentile of corn yield is 190 percent larger than the 5th percentile yield

Suri, Tavneet, and Christopher Udry. 2022. "Agricultural Technology in Africa." Journal of Economic Perspectives, 36 (1): 33-56. DOI: 10.1257/jep.36.1.33

Abstract: We discuss recent trends in agricultural productivity in Africa and highlight how technological progress in agriculture has stagnated on the continent. We briefly review the literature that tries to explain this stagnation through the lens of particular constraints to technology adoption. Ultimately, none of these constraints alone can explain these trends. New research highlights pervasive heterogeneity in the gross and net returns to agricultural technologies across Africa. We argue that this heterogeneity makes the adoption process more challenging, limits the scope of many innovations, and contributes to the stagnation in technology use. We conclude with directions for policy and what we feel are still important, unanswered research questions.

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Excerpts:

Farmers who were provided with plot-specific recommendations for appropriate fertilizer use (along with vouchers for reduced cost access to inputs) were more likely to apply the recommended fertilizer, and increased yields by over 150 percent relative to the control group.

Claassen and Just (2011) study the variance of log yield across farms in the United States: they find that the 95th percentile of corn yield is 190 percent larger than the 5th percentile yield.