Book excerpt: Informal relations have been one of the major research topics of the social sciences since the 1990s. In order to allow for meaningful comparisons between different combinations of the positive and negative effects of informal relations on democratic representation, this book focuses on post-socialist Central and Eastern Europe as a particular region where formal democratic rules have been established, but competing informal rules are still strong. A broad spectrum of related analytical concepts is discussed from different perspectives and from different academic disciplines, then empirical cases of the relationship between informal relations and democratic representation are analyzed. The contributions span the whole continuum, as we perceive it, from civil society networks seen as supporting democratic representation to the perversion of democratic representation through political corruption. The final part of the book takes a closer look at corruption through four case studies from Russia.