This article explores the determinants for the maintenance of ethnic identity by comparing six groups of migrant Germans. The groups are 18th century German peasants migrating to Volga Russia, 13 century migrants to Latvia, 17th century bureaucrats and traders migrating to Moscow/St Petersburg, 18th century peasants migrating to Pennsylvania, 19th century Hutterite migrants to the North American Midwest, and 18th century Volga German migrants to the American Midwest. Notably, three of these groups assimilated into the host society, while three of them formed ethnic enclaves. Comparison of the six cases indicate that what determined whether a group would maintain its identity or not depended on whether individuals could move their inheritable economic base. This is because in the immigrant situation it is the inheritable economic base which determines who the primary reference group will be. -Author