Which rose first: the price of chicken or corn? Sumner comments on shifting markets

Broilers by Michael Czarick

Marketplace / May 11, 2021

“So China has turned to U.S. corn, and that drives prices in the United States,” said agriculture professor Daniel Sumner at University of California, Davis.

He said American farmers have been growing more corn to meet demand, so they have less room for other crops.

“Corn takes land away from wheat. Well, that reduces wheat supply, and you increase the price of wheat as a consequence,” Sumner said.

Click here for the full article.

Virus’ long-term impact will be mixed for ag, economist says

Western FarmPress / March 16, 2020

Production activities will continue, but California’s high-end wines and non-staple foods will take a hit.

Even in self-imposed isolation, people “are still going to eat,” which is why agricultural production in general “is not very income-sensitive,” said Dan Sumner, director of the University of California’s Agricultural Issues Center in Davis.

Click here for the full article.

Are There Yield Benefits With Genetically Engineered Corn?

Colin A. Carter, Xiaomeng Cui, and Dalia Ghanem
from ARE Update Vol. 21, No. 2, Nov/Dec, 2017

View Full Article PDF


A New York Times article entitled “Broken Promises of Genetically Modified Crops,” recently showed that U.S. and Western European corn yields have followed similar trends over the past two decades. This was taken as evidence that genetically modified (GM) crops have no yield benefits, since most of
Western Europe does not grow GM corn. We believe this conclusion is inaccurate because the yield comparison is flawed.

Crop supply dynamics and the illusion of partial adjustment

Abstract: We use field-level data to estimate the response of corn and soybean acreage to price shocks. Our sample contains more than 8 million observations derived from satellite imagery and includes every cultivated field in Iowa, Illinois, and Indiana. We estimate that aggregate crop acreage responds more to price shocks in the short run than in the long run, and we show theoretically how the benefits of crop rotation generate this response pattern. In essence, farmers who change crops due to a price shock have an incentive to switch back to the previous crop to capture the benefits of crop rotation. Our result contradicts the long-held belief that agricultural supply responds gradually to price shocks through partial adjustment. We would not have obtained this result had we used county-level panel data. Standard econometric methods applied to county-level data produce estimates consistent with partial adjustment. We show that this apparent partial adjustment is illusory, and we demonstrate how it arises from the fact that fields in the same county are more similar to each other than to fields in other counties. This result underscores the importance of using models with appropriate micro-foundations and cautions against inferring micro-level rigidities from inertia in aggregate panel data. Our preferred estimate of the own-price long-run elasticity of corn acreage is 0.29, and the cross-price elasticity is −0.22. The corresponding elasticities for soybean acreage are 0.26 and −0.33. Our estimated short-run elasticities are 37% larger than their long-run counterparts.

Crop Supply Dynamics and the Illusion of Partial Adjustment. Nathan P. Hendricks, Aaron Smith and Daniel A. Sumner, American Journal of Agricultural Economics 2014.

Copyright © The Regents of the University of California, Davis campus. All rights reserved.