"Reductionist" (i.e., most economic) theories of collective action explain acts like voting by individual incentives, perhaps including "social" phenomena via payoff terms like social pressure or warm glow.
A short thread about an (old) complaint about such theories.
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A reductionist theory might say: when you vote, you're almost certainly not pivotal, but you value praise for helping, or you just like the identity of standing for X.
BUT: "praise," "blame," and "identity" are not individualistic ideas.
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Praise, blame, identity, etc. make sense only in a community and a culture that gives them meaning.
"Individualistic" accounts with these special payoff adjustments are incomplete without some engagement with the sources of those "non-individualistic" reasons and motives.
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Some scholars would like to understand everything about these collective/cultural ideas through evolutionary (or similar) theories that ultimately come down to material payoffs. "Our norms evolved because that's how our community gets the most food," etc.
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But this kind of reductionism seems goofy: it feels like trying to understand why we have the kind of poetry or pop music we have in terms of what gets us the most food. The explanatory tool doesn't feel compatible with the task.
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At best such a theory may explain that we have poetry, but not what kind of poetry we have.
This already suggests the limits of "methodological individualism" in understanding the actual content of our social practices.
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Once we realize that the details of the "warm glow" or "responsibility" term in individual payoffs is where all the action is, we are forced to start thinking less like economists and more like sociologists.
We have to take the group's "thinking" about itself seriously.
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And we may have to understand a group's motives in terms of the values that they say they have, rather than some values that we as analysts bring in our toolkit.
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To sum up, many "individualistic" theories punt all the content to the ethical/identity payoff terms.
If we want to say anything about those terms, we have to take them seriously. And they're not individualistic things --and probably not reducible to individualistic things.
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PS/ This is mostly plagiarizing sociologists (shout out to Mark Granovetter who spent a term griping about economists and their methodological individualism) and some essays by Bernard Williams.
PPS/ Here, more specifically, is one thing I'm plagiarizing (from Williams, Truth and Truthfulness)
and a related bit:
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A thread on what we can learn about polarization of opinions from a simple behavioral network model.
Remember the DeGroot model? It says you decide what to think tomorrow by taking an average of what you and your friends think today.
Examples:
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Here is a condensed way of writing it using vector notation, which turns out to be very useful!
Here W has no negative entries, and each row sums to 1 (that's called "row-stochastic"). That makes sense, since each person is averaging others' views.
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We often want to think of the weights as coming from a social network, maybe something like this. The network tells you who are the friends that you listen to.
So we'd better establish a way of thinking of the updating weights as coming from a network.
Suppose two people each have some private information about, say, a stock. The first says her posterior expectation of its price, then the second learns from her statement and says his, etc.
Will they reach a consensus? Under common priors, yes. (See below.)
People often learn this from GP (below), but they assume finite probability spaces & really use that.
Tweet proof shows that convergence to consensus doesn't rely on finiteness, and holds much more generally. (When was the martingale proof first written down?)
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If we do assume each of us has a finite partition of the states, the tweet proof immediately implies convergence in finitely many steps:
our partitions can only change finitely many times, given that convergence happens, it must happen in finite time.
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An application of Aumann's agreeing-to-disagree result: certain kinds of war between rational countries are puzzling.
Since war involves destruction, better for one to surrender and bargain. But maybe each believes it'll get more by fighting? Suppose a country fights iff
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it thinks it will win with prob > 0.5. In the notation below, let X = indicator that I win. Then war means it's common knowledge that Y>.5>Z.
That's impossible, but the proof below doesn't quite show it. Exercise: show there's no CK event E on which Y>Z.
War here is like speculative trade (cf. no-trade theorem): it can't happen due to different information ALONE, because by Aumann both of us can't rationally expect to win.
Thus, if war is zero-sum or worse, it entails irrationality or different priors.
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One of my favorite things about Bob Wilson, co-winner of today's prize, is how gentle a giant he is, how modest yet understatedly charismatic and funny. This rare recording gives a sense.
"I'm here to today to argue that sequential equilibrium [his own invention with Kreps] -- which you said ... in 1982 completed the answer to the questions that Luce and Raiffa raised in 1957 -- well, MY stance was that that was a mild disaster!
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"Sequential equilibrium turned out to have enormous flaws. And the revelation of those flaws has, I think, been actually opening up what the real challenge is for game theory in terms of establishing what its foundations are.
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