Ludwig von Mises, Economic Calculation in the Socialist Commonwealth

"When it first appeared in 1920, Mises was alone in challenging the socialists to explain how their pricing system would actually work in practice. Mises proved that socialism could not work because it could not distinguish more or less valuable uses of social resources, and predicted the system would end in chaos. The result of his proof was the two-decade-long 'socialist calculation' debate." From http://mises.org/document/448/Economic-Calculation-in-the-Socialist-Commonwealth (also source of work)