Economists have long understood the dynamic at work here. Marx and other socialists thought that those in charge of the planning process, and for Marx that was the whole community, could rationally determine what to produce and how best to produce it in the absence of markets, exchange, and prices. Since Mises’s famous essay in 1920, however, we have known that doing so is not possible.
Genuine market prices are necessary for people be able to make determinations of value in anything larger than a household. Without prices, there is no way to know, not just what people value but (more importantly) how to make what they value using the least valuable resources possible.
In other words, rational production decisions are impossible without market prices, and market prices can’t exist without exchange and therefore there has to be private ownership, especially of the means of production.
But what happens when those given the power to make such decisions realize they cannot achieve their perhaps well-intentioned goals? The power does not go away. More often than not, the first reaction is precisely what we’ve seen in Venezuela: crack down harder on producers for not living up to impossible demands and ration goods to punish consumers for “hoarding.” And when that doesn’t work, go to more draconian authoritarianism, and do whatever it takes to hold on to power.
After a while, these exercises of brute power have consequences. They attract those with a comparative advantage in exercising such power (and perhaps those who have a high consumption value for doing so) into positions of power. Marxism is not Stalinism, but the inability of Marxian socialism to live up to its promises creates the conditions that make Stalinism possible and likely. In other words, Stalinism is an unintended consequence of Marxian socialism.
In addition, as state control becomes more clearly ineffective, people start to work around it by establishing distorted forms of market exchange. Bribery of politicians and bureaucrats, threats to producers, cronyism, and nepotism all become the ways of getting things done. Scarce resources have to be allocated somehow, and markets are like weeds in that they will grow in the cracks left by the failures of planning.
To the outside world, corruption and poor implementation caused socialism to fail. But that gets matters completely backward: corruption and ineffective political actors are not the cause of socialism’s failure, but a result of that failure. When you make real markets illegal and when your attempts at planning inevitably fail, what you get is the bribery and corruption of black markets. Once again, these are not what Marxism intends, but they are an inevitable unintended consequence.