Well, if we want to compare apples with apples, I would suggest the following taxonomy of economies:
A. Centrally-Planned Economies B. Plan-Heavy Economies with Some Worker Control C. Social-Market Economies D. Free-Market Economies
And the following taxonomy of polities:
1. Pure Totalitarian Terror 2. Authoritarian Dictatorship 3. Oligarchic Politics 4. Party-Centered Mass Politics 5. Media-Centered Mass Politics 6. A Free Society of Associated Producers
We have lots of examples of A1 and A3. We have one example (Yugoslavia) of B2. I will defer to others as to whether pre-1989 Hungary counts as B3 and whether China today is B3 or C3. We certainly have examples of C1 and lots of examples of C2, D2, C3, and D3. And we have some examples of C4, C5, D4, and D5.
But damned if I can think of an example of A4, B4, A5, or B5 (with the caveat that Nicaragua or Chile *might* have been able to develop into one if left alone).
And I see no examples of 6.
All in all, I think--following Roberto M. Unger--that the links between economic systems and political possibilities are not as strong as we usually imagine. But I don't doubt that the links are there, and that I don't understand them.
Brad DeLong