Economic Problems of Socialism in the USSR is a work of Marxist-Leninist Political Economy written by Josef Stalin in 1951. It was one of the last works published before his death. In it he made the claim that the USSR had reached the lower stage of communism.
The main impetus for the book came from the discussions around the preparations for a new textbook on Marxist Political Economy, that would be standard throughout the Communist Movement. One of the main theoretical debates was on whether the Law of Value still operated within a socialist economy. Some economists claimed that Marx in Das Kapital had only meant for it to apply to capitalist exchange. Stalin however insisted that it still operated under a socialist economy. Nonetheless he argued that it was a historical and not eternal law, and would disappear in the 2nd higher stage of communism. Under socialism it was necessary for commodity exchange and trained "business executives to conduct production on rational lines and disciplines them".
Ironically, early Market Socialist economists in both the USSR and China would use these words of Stalin to justify market reforms.
Xue Muqiao in his 1981 work China's Socialist Economy would use Stalin's book as a justification for using the market mechanism in the Primary stage of socialism.
Xue Muqiao introduced the term "underdeveloped socialism" in his book China's Socialist Economy. The book was written in the orthodox Marxist–Leninist framework enunciated by Joseph Stalin in Economic Problems of Socialism in the U.S.S.R. (1952). Xue wrote that within the socialist mode of production there were several phases and for China to reach an advanced form of socialism it had to focus on developing the productive forces. He proposed a theory in which the basic laws of economic growth were those in which "the relations of production must conform to the level of the productive forces". Similar to Stalin, Xue considered the productive forces to be primary and that the relations of production had to conform to the level of the productive forces. Xue believed that this was a fundamental universal law of economics.