The OECD has been collecting information on fisheries policies for many years. The Fisheres Suppor Estimate (FSE) database represents the latest version of its fisheries policy inventory and classification system. This database contains information on policies in 33 countries (representing about half of global fisheries landings) totalling USD 13 billion in support expenditures. A policy impact model has been developed to use this data to investigate how different types of support can effect fishing effort, stocks, incomes and fleet size. This presentation will explain the economic rationale behind the FSE classification system and present the structure and results of the associated policy impact model. These results consider the relative impacts of policies based on the purchase of fuel, inputs such as fishing gear, vessel construction, fish prices and fisher income.