Assessing the Land Use Changes and Greenhouse Gas Emissions of Biofuels: Elucidating the Crop Yield Effects

Available estimates of the land use changes and greenhouse gas emissions of biofuels differ significantly across economic models. This paper focuses on the impacts of price-induced yield assumptions on U.S. corn ethanol results. These assumptions have dramatic impacts within the FAPRI modeling framework, but limited ones within the GTAP-BIO model. I show that these sensitivity to yield assumption results are not comparable because the ex ante land and production elasticities assumed in these two models are not comparable. The analysis reveals that the current focus solely on the value of the price-induced yield elasticity can be misleading.