Socialism is strictly “impossible.” Its impracticability is not, as Bryan Caplan has suggested, a “quantitative” matter, nor does he show that real‐world socialism's incentive problems outweighed its informational ones. Caplan's criticism of Ludwig von Mises's critique of the “possibility” of socialism fails to appreciate what he meant by “socialism” and misunderstands Mises's argument about economic calculation. History, too, suggests that socialism's informational deficiency was the most significant problem facing those who tried to implement socialism.

Socialism is strictly “impossible.” Its impracticability is not, as Bryan Caplan has suggested, a “quantitative” matter, nor does he show that real‐world socialism's incentive problems outweighed its informational ones. Caplan's criticism of Ludwig von Mises's critique of the “possibility” of socialism fails to appreciate what he meant by “socialism” and misunderstands Mises's argument about economic calculation. History, too, suggests that socialism's informational deficiency was the most significant problem facing those who tried to implement socialism.