The book is the first to provide a systematic overview of the interplay of formal and informal institutions as elements of the Russian federalism from the early 1990s to the mid-2010s. It discusses the crucial role of informal power structures and practices in the relations between the center and the regions in Russia, which survived the centralization policy of the Putin government. Using econometric large-N analysis and a set of novel quantitative indicators, the book shows that persistence of informal autonomy in Russia has mostly harmful consequences for the political development of the regions, contributing to the consolidation and strengthening of sub-national autocracies.