Modern biotechnology can produce genetically modified crops that are more productive or provide qualities some consumers might prefer. This article presents a partial equilibrium model of international agricultural commodity trade, which is used to examine the effects on producer returns of productivity, consumer preferences, and uptake rates of genetically modified crops. Both first- and second-generation genetically modified crops are considered. The analysis focuses on gross returns to agricultural producers in Australia, the European Union, New Zealand, and the United States. Results suggest that these regions are affected differently by productivity changes and consumer reactions to genetically modified crops.