The book analyzes concentrations of wealth and power in developed democracies. It shows that economic measures, which states adopted during the 1980s and 1990s, had evolved first into liberal oligarchy, and later, after the 2007-2008 global financial crisis, into illiberal and populist oligarchy. The shape and content of these two kinds of oligarchy have been determined largely because of practices and political strategies that powerful state and market actors employed. This project will appeal to a wide audience including academics, researchers, students, and anyone who is interested in oligarchy political power, IR, political economy, and sociology.