approximately 30 million are iIIegals. The book consists of eight papers which are allocated to five parts: Theoretical Models (Part I), Performance of Migrants (Part 11), Migration Within Developing Countries (Part IV) and Immigration Policy (Part V)' Each paper begins with a brief summary of its content. Part I, Theoretical Models, contains first "A Microeconomic Zlmm.r-mann VI Model of Migration" by Siegfried Berninghaus and Hans-GUnther Seifert-Vogt. They study migration decision making under incomplete information and apply it to empirically relevant phenomena. The second paper by Gerhard Schmitt-Rink "Migration and International Factor Price Equalization" demonstrates that international migration tends to equalize national factor prices and factor shares even in the absence of international trade. In Part II, Performance of Migrants, Lucie Merkle and Klaus F.