Department of Agricultural and Resource Economics

Increased demand for agricultural produce for food, fiber, feed, and energy generates a tradeoff between high prices and environmentally costly land conversion. Genetically engineered (GE) seeds can potentially increase supply without recruiting new lands to production. We develop a simple adoption model to show how first-generation GE increases yield per hectare. We identify yield increases from cross country time series variation in GE adoption share within the main GE crops- cotton, corn, and soybeans. We find that GE increased yields 34% for cotton, 32% for corn, but only 2% for soybeans. The model also predicts that GE extends the range of lands that can be farmed profitably. If the output on these lands are attributed to GE technology, then overall supply effects are larger than previously understood. Considering this extensive margin effect, the supply effect of GE increases from 10% to 16% for corn, 15% to 20% for cotton, and 2% to 39% for soybeans, generating significant downward pressure on prices. Finally, we compute \saved" lands and greenhouse gasses as the difference between observed hectarage per crop and counterfactual hectarage needed to generate the same output without the yield boost from GE. We find that all together, GE saved 21million Ha of land from conversion to agriculture in 2010, or 0.41 Gt ofCO2emissions (using a constantCO2/land conversion factor). These averted emissions are equivalent to roughly 1/3 the annual emissions from driving in the US.