Individuals' preferences in transition regions are still shaped by the former communist system. We test this 'communist legacy' hypothesis by examining the impact of acculturation in a communist regime on social network participation and, as a consequence, on preferences for spatial mobility. We focus on the paradigmatic case of Eastern Germany, where mobility intentions seem to be substantially weaker than in the Western part. Applying an IV ordered probit approach we first find that Eastern people acculturated in a communist system are more invested in locally bounded informal social capital than Western people. Second, we confirm that membership in such locally bounded social networks reduces the intention to move away. Third, after controlling for the social network effect the mobility gap between East and West is substantially reduced. Low spatial mobility of the Eastern population, we conclude, is to an important extent attributable to a social capital endowment characteristic of post-communist economies.