Socialism, efficiency and the One Big Cartel

In the production sphere, socialism is equivalent to One Big Cartel, compulsorily organized and controlled by the State. Those who advocate socialist “central planning” as the more ef­ficient method of production for consumer wants must answer the question: If this central planning is really more efficient, why has it not been established by profit-seeking individuals on the free market? The fact that One Big Cartel has never been formed voluntarily and that it needs the coercive might of the State to be formed demonstrates that it could not possibly be the most efficient method of satisfying consumer desires.

...says Rothbard in Man, Economy and State (chapter 10). The socialist will never attempt to answer the question raised by Rothbard, because he can't. Actually, socialists don't highlight their "efficiency" argument so much anymore. Now they say: "Well, socialism isn't really that efficient, but we will impose it anyway in the name of "justice", so that everyone can suffer equally under the inefficiency of socialism."