The spatial distribution of modern varieties, and the genes they embody, has economic value because it affects crop productivity from year to year. Since farmers choose varieties based on observable traits rather than the genes they cannot see, a first step in understanding the spatial...

The overall goal of this study is to determine the extent by which genetically engineered (GE) crops in China can lead to reductions of pesticide use, the nature and source of the reductions, and whether or not there are any non-pecuniary externalities. One of the first studies of the effect of...