We explore the economic implications of the possible Turkish accession to the European Union. We focus on three main changes associated with Turkish membership: (i) accession to the internal European Market; (ii) institutional reforms in Turkey triggered by EU-membership; and (iii) migration in response to the free movement of workers. Overall, the macroeconomic implications for EU countries are small but positive. European exports increase by around 20%. Turkey experiences larger economic gains than the EU: consumption per capita is estimated to rise by about 4% as a result of accession to the internal market and free movement of labour. If Turkey would succeed in reforming its domestic institutions in response to EU-membership, consumption per capita in Turkey could raise by an additional 9%. These benefits would spill over to the EU.