The phenomenon of East-West European migration was largely neglected in the past by researchers and policy makers, but it has recently become a controversial and important topic for the international community. This volume is the first comprehensive, combined socio-economic and political analysis of the trends and mechanisms of international migration from and into Poland since 1945, from the point of view of the forthcoming enlargement of the European Union. The author describes indepth the mechanisms of population processes in the period before the collapse of Communism and during the transition period that followed. Special emphasis is placed on the movement of people into Poland, people who after EU enlargement would be excluded from the expanded Western European migration system. The author examines how major political and social events such as the collapse of Communist rule and political and economic transformation have affected population phenomena and in a relatively short space of time, have reversed stabilized migration trends.