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Disclaimer. Don't rely on these old notes in lieu of reading the literature, but they can jog your memory. As a grad student long ago, my peers and I collaborated to write and exchange summaries of political science research. I posted them to a wiki-style website. "Wikisum" is now dead but archived here. I cannot vouch for these notes' accuracy, nor can I say who wrote them.
List and Goodin. 2001. Epistemic democracy: Generalizing the Condorcet jury theorem. Journal of Political Philosophy 9.
List and Goodin introduce the Condorcet Jury Theorem, which argues that under certain plausible conditions, proper voting rules do track the truth--that is, they produce the "correct" outcome. Condorcet's logic, then, can be extended beyond a binary choice; since the logic holds, then if the assumptions are true, then the conclusions of the theorem will be true. (This article leaves unanswered whether the assumptions are true.) This article is most useful as an introduction to the CJT, though it also includes an interesting discussion of plurality rule. See also Wikipedia's article on Condorcet's jury theorem.
The Condorcet Jury Theorem (CJT) can be used to explain the truth-tracking properties of voting. If individuals are (on average) more likely to make correct decisions than incorrect ones, then large groups of them will be very likely to make correct decisions via majority/plurality voting mechanisms.
People discuss democracy in two ways. 'Epistemic democrats", like Rousseau, wish for a governing mechanism that will "track the truth"--that is, satisfy some objective standard. 'Procedural democrats', like Dahl and Schumpeter, are more interested in the rules of the game, regardless of the outcome. When it comes to a majoritarian choice between two alternatives, epistemic and procedural democrats have no need to disagree; Condorcet's jury theorem long ago showed that, as long as the average voter has at least a 50% chance of making the (epistemically) "correct" decision, majoritarianism works. The authors' main contribution is to argue that most other democratic procedures (with more than two options) also "work" under the same assumption, and they all work equally (more or less) well. Thus, plurality rule, the Borda count, etc all work as "truth trackers." We need not worry about epistemic debates, then, when deciding what sort of democracy to have.
"If each member of a jury is more likely to be right than wrong, then the majority of the jury, too, is more likely to be right than wrong; and the probability that the right outcome is supported by a majority of the jury is a swiftly increasing function of the size of the jury, converging to 1 as the size of the jury tends to infinity" (page 283).
This article shows only that Condorcet's logic holds. Thus, if the assumptions are true, the conclusions are true. This article does not claim that the assumptions are true, though, only that the logic is correct. So we cannot apply the theorem of one of these three objections to the assumptions is correct:
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Tags
List, Christian (author) • Goodin, Robert E (author) • Political Theory • Democracy • Social Choice • Voting • Normative Theories of Voting
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