The integration of the Central and Eastern European transition countries into the European Union is one of the most exciting economic policy issues of today. The book provides a detailed analysis of the economic effects which EU integration has on accession countries. It shows that these countries have already managed to fully remove the anti-trade bias with the EU that existed before the fall of the iron curtain. Benefits from further integration into the EU could result in particular from the fact that full membership in the European Community will increase the credibility of government policy in accession countries. The study explores in depth how these credibility effects can be quantified. The author develops a novel approach to model the transformation process within a dynamic computable general equilibrium framework. Furthermore, he estimates the potential income and welfare effects of EU integration for Poland, the largest transition country with EU candidate status.