Brad DeLong recently compared the economic performance of communist countries with their capitalist neighbors and found, surprise surprise, that capitalism works a lot better than communism:
Eschewing markets robs you of between 80% and 90% of your potential economic productivity.
DeLong’s argument is persuasive, but it also seems a bit dated. Outside of a few English departments pretty much everyone recognizes that communism was a flop. Heck, even Fidel Castro admits that it doesn’t work. Today the pressing question is not America vs. the Soviet Union but America vs. the European Union, i.e. the relatively free market system of the United States vs. the relatively more social democratic system of many European countries.
Here is some recent OCED data on median income by country, from the mid 2000S