Some socialists such as H. D. Dickinson and Oskar Lange, responded by invoking general equilibrium theory, which they argued disproved Mises's thesis. They noted that the difference between a planned and a free market system lay in who was responsible for solving the equations. They argued, if some of the prices chosen by socialist managers were wrong, gluts or shortages would appear, signalling them to adjust the prices up or down, just as in a free market. Through such a trial and error, a socialist economy could mimic the efficiency of a free market system, while avoiding its many problems.
What did some socialists bring up as a rebuttal to Hayek's resource distribution argument? What did socialists believe equilibrium theory invalidated? According to those who argued against Hayek, what sets planned and free markets apart is what? What type of economic system did the socialists want to avoid?