Job-related spatial mobility is a subject of great importance in Europe. But how mobile are Europeans? What are the consequences of professional mobility for quality of life, family life, and social relationships? For the first time, these questions are analyzed on the basis of the findings of a large-scale European survey. The contributions in Volume I are directed at the diversity and the extent of mobility in six European countries - Germany, Spain, France, Poland, Switzerland, and Belgium. In Volume II (due early in 2009), the causes and determinants of job mobility and their individual and social consequences are analyzed in cross-national comparisons.