The welfare implications of intellectual property protection (IPP) for private sector agricultural research are analyzed, focusing on the realistic cases in which countries provide different IPP levels, technology spills over across countries, and the public sector is involved in research. A model is developed to determine who benefits from, and who should pay for, the associated research. The paper contains some interesting results on the implications of a harmonization of IPP policies through multilateral agreements or via technology that allows research firms to prevent the copying of plants and animals that express traits that have emerged from their research.