This book aims to shed new light on the puzzle of the late Soviet conversion to the market and capitalism by revisiting the history of Soviet reform economics. Using a variety of sources, including interviews with economists, archival files, and published materials, it examines the social contexts in which economists employed in economic administration and research institutions could have played a crucial public and political role, the forms of their participation, and the social and political logic behind the selection of economic experts and their rise to power during perestroika and the transition period. It also compares the professional trajectories of these reformist economists and assesses the scope of this group's influence in the post-Soviet period in order to conclude on the new state of economic expertise in Russia. Olessia Kirtchik obtained her doctoral degree in sociology from the School for Advanced Studies in the Social Sciences (EHESS), in Paris, France. In 2012-2022, she was a Leading Research Fellow at the Poletayev Institute for Historical and Theoretical Studies in the Humanities (IGITI) at the Higher School of Economics, Moscow, Russia. She has published extensively on the social history of economic sciences and reforms in the Soviet Union and Russia, on the scientific and technological cooperation and circulations of knowledge during the Cold War (including in Europe-Asia Studies, History of the Human Sciences, History of Political Economy, Studies in History and Philosophy of Science, Politix, Revue d'Anthropologie des Connaissances).