The Soviet Union’s New Economic Policy in 1921 was a form of mixed economy, in which the market played a real role.
The nearest the Soviet Union ever came (and it wasn’t very near) to a properly productive economy was during the period when, out of desperation, the struggling new state adopted its New Economic Policy in 1921. This was a form of mixed economy, in which the market played a real role. The NEP worked very well under the circumstances (markets are a remarkable thing) until Stalin brought it to a brutal end.
In 1922, speaking at a congress in Moscow, Lenin discussed the NEP, its ideological significance, and something rather striking about the way that it worked:
The state is in our hands; but has it operated the New Economic Policy in the way we wanted in this past year? No. But we refuse to admit that it did not operate in the way we wanted. How did it operate? The machine refused to obey the hand that guided it. It was like a car that was going not in the direction the driver desired, but in the direction someone else desired; as if it were being driven by some mysterious, lawless hand, God knows whose, perhaps of a profiteer, or of a private capitalist, or of both. Be that as it may, the car is not going quite in the direction the man at the wheel imagines, and often it goes in an altogether different direction.
The “mysterious hand” strikes again.