Scientific analysis is essential to assess biofuel policy effects: in response to the paper by Kim and Dale on "Indirect land use change for biofuels: Testing predictions and improving analytical methodologies"

Vigorous debate on the effects of biofuels derives largely from the changes in land use estimated using economic models designed mainly for the analysis of agricultural trade and markets. The models referenced for land-use change (LUC) analysis in the U.S. Environmental Protection Agency Final Rule on the Renewable Fuel Standard include GTAP, FAPRI-CARD, and FASOM. To address bioenergy impacts, these models were expanded and modified to facilitate simulations of hypothesized LUC. However, even when models use similar basic assumptions and data, the range of LUC results can vary by ten-fold or more. While the market dynamics simulated in these models include processes that are important in estimating effects of biofuel policies, the models have not been validated for estimating land-use changes and employ crucial assumptions and simplifications that contradict empirical evidence.