As part of a cooperative agreement with the United States Department of Agriculture (USDA), the George Washington University Regulatory Studies Center produced a five-chapter report on regulatory differences between the United States (U.S.) and the European Union (EU) and their effects on agricultural productivity. Those chapters are published here as a working paper series with five parts. This chapter provides focuses on the impact of agricultural policy, specifically regulation, in influencing agricultural productivity across jurisdictions. It begins by tracing agricultural growth in the EU and U.S. to illustrate their respective trends for agricultural productivity. Then, drawing from the literature, it identifies measures and methodologies used to estimate the impact of regulation on productivity. Finally, it outlines important differences regarding how regulations can affect agricultural productivity and other measures of agricultural performance such as output and production costs in the EU and the U.S.