Oskar Ryszard Lange 1904-1965

When Lange was at the University of Michigan in the United States in the 1930s, he engaged in a debate with Hayek, who was at the University of London, regarding the feasibility of socialism. Because Lange understood the functions of the market well, he was likely skeptical about denying them. His writings criticizing the excesses of a planned economy suggest this.
Certainly, it is difficult without reviving the market, but discussions regarding the function of profit arose in both the Soviet Union and China. Arguments that reviving the function of profit was necessary to advance socialism more efficiently emerged in both countries.
In the Soviet Union, the Communist Party was dismantled, radical marketization proceeded, and oligarchs were born. This led to the birth of Putin's authoritarian regime. In China, the Communist Party was preserved, and marketization proceeded gradually. However, that was the path under the dictatorship of the Communist Party, leading to the authoritarian regime of Xi Jinping.
The common error in the Soviet Union and China is the insufficient guarantee of rights such as freedom of speech, thought, and the press for their citizens. They have not realized a parliamentary system that recognizes the existence of political parties opposed to the regime, they have not operated the government by valuing parliaments chosen through transparent elections, and furthermore, the activities of organizations that criticize the shortcomings of the parliament and freely report on socio-economic issues are not permitted.

Lange By David R. Henderson
Cited from Econlib.com
The author is a professor emeritus at the Naval Postgraduate School and a research fellow at the Hoover Institution at Stanford University.

Polish economist Oskar Lange is best known for his contributions to socialist economics. His views on the feasibility of socialism (feasibility) advanced and retreated throughout his life. In 1934, at the University of Krakow, he and co-author Marek Breit outlined socialism as a system where the government owns all factories, and each industry is organized as a monopoly called a public trust. (In this system,) workers would have a significant say in the management of each industry.
Lange left Europe in 1935 to teach at the University of Michigan. In 1936 and 1937, he engaged in a debate with Friedrich Hayek regarding the feasibility of socialism. There, he introduced market socialism, where the government owns major industries and a Central Planning Board (CPB) sets the prices for these industries. The CPB would raise prices to avoid shortages and lower prices to avoid surpluses, changing prices to ensure (supply and demand) are in equilibrium. Hayek pointed out that, as Lange demonstrated, the government setting prices to mimic competition appears inferior to the existence of real competition.
In 1943, Lange moved to the University of Chicago. That same year, he proposed to the Polish government that key industries be socialized, but that farms, shops, and many other small and medium-sized industries remain in private hands. (He argued that) a large private sector is essential to preserve the flexibility, plasticity, and adaptability that only private initiative can achieve.
In 1945, the newly established communist regime in Poland appointed Lange as ambassador to the United States. In 1946, he became the Polish representative to the United Nations. In 1949, when Stalinist orthodoxy was imposed on Poland, Lange was recalled to Poland and given a lower academic position. In 1953, while Poland was still under Stalinist repression, Lange reversed his (academic position) and wrote a paper praising Stalin's totalitarian economic control.
In 1955, after political repression eased slightly, Lange became a professor at the University of Warsaw and chairman of the Polish State Planning Commission.