[2] He responded to the economic calculation problem proposed by Ludwig von Mises and Friedrich Hayek by claiming that managers in a centrally-planned economy would be able to monitor supply and demand through increases and declines in inventories of goods, and advocated the nationalization of major industries.

[6] Joseph Stalin, who identified Lange as a person of leftist and pro-Soviet sympathies, prevailed on President Franklin D. Roosevelt to obtain a passport for Lange to visit the Soviet Union in an official capacity, so that Stalin could speak with him personally; he also proposed offering him a position in the future Polish cabinet.

Lange returned to the United States at the end of May and met, at Roosevelt's request, with Prime Minister Stanisław Mikołajczyk of the government-in-exile, who was on a visit in Washington.

[7] Towards the end of World War II, Lange broke with the Polish government-in-exile and transferred his support to the Lublin Committee (PKWN) sponsored by the Soviet Union.

He then renounced his American citizenship and went back to the US in the same year as the Polish People's Republic's first ambassador to the United States.

[6] Oskar Lange worked for the Polish government while continuing his academic pursuits at the University of Warsaw and the Main School of Planning and Statistics.

In the book, Lange advocated the use of market tools (especially the neoclassical pricing theory) in economic planning of socialism and Marxism.

Under this system, central planners would arbitrarily pick a price for products manufactured in government factories and raise it or reduce, depending on whether it resulted in shortages or gluts.

Lowering the prices would encourage businesses to curtail production in order to prevent losses, which would eliminate the surplus.

[10] Hayek's essay entitled The Use of Knowledge in Society is a rebuttal to Lange's work and is considered one of the most important articles ever written in the field of economics.