The whole point of Marxism was that market economy is crap and communist economy is going to be much more effective.
Since 30's USSR was unable not only to compete but even catch up with Western economies, specifically due to central planning and ideologic bias. It survived the WW2 only to help from Allies and then since 60's it was living of Western loans and exploitation of its colonies - while bashing the "imperialist economy" in the press all the time.