This is the third of seven volumes comprising the definitive scholarly edition of the works of Michał Kalecki, one of the most distinguished twentieth-century economists and one of the trio who arrived at the conclusions promulgated by Keynes around the time - and in Kalecki's case arguably earlier - than Keynes himself.Nearly half the material to appear in the seven volumes has never been previously published in English and includes revisions and additions made in the light of recent research, including information about the relationship of Kalecki's ideas to the ideas of contemporary economic theory.This third volume contains Kalecki's studies on the functioning of the socialist economy and on long-run planning, with special reference to Poland. Kalecki made an extensive contribution to the debates on Poland's post-war reconstruction, and especially on the system of planning and management of the Polish economy in 1955-64 and much of his work was unpublished until the 1980's. His activities throughout this period were so varied - on the practical level as well as on the theoretical - that the volume contains nearly all the material which has survived - Kalecki's correspondence, notes, records of his contribution to debates, and memoranda, providing an opportunity to survey Kalecki's activities related to the functioning of the Polish post-war economy.