On Mar 11, 2010, at 8:50 AM, Brian Olson wrote: > On Mar 11, 2010, at 11:29 AM, Jonathan Lundell wrote: > >> As with any choice system based on cardinal utility, there end up being two >> problems that are not, I think, amenable to solution. One is the >> incomparability of individual utility measures from voter to voter (and here >> we're talking about utility deltas, since the utilities are normalized to >> max=1.0). The other is that, even if comparability were solved, we don't >> have a means of, in the individual case, determining what they are. > > Arrow made the same mistake. We can't compare interpersonal utility, but in > practice we do. We set everyone's utility to One. One person one vote. That's > how much you get. > >> In particular, reported utility isn't very useful, since for the system to >> work, we need sincere utility, and a utility-based system provides every >> incentive to strategize. And, as Terry suggests, it's not clear what we >> *mean* by utility here. Happiness with what? The outcome of the individual >> election? The makeup of the resulting legislature? The legislation resulting >> from that legislature? > > Reported utility is vulnerable to all kinds of noise, imperfect reporting, > imperfect introspection, and so on. And yet this can be simulated. We can > make sim people who are perfectly knowable, add that noise, run the election, > and see what happens both compared to the noisy utility and true utility. > When I did this it turns out there are some methods less vulnerable to noise! > (Condorcet better, IRV, with it's non-monotonic threshold swing regions is > more vulnerable to noise.) > >> And even if we could somehow measure the voter's ultimate happiness as a >> function of legislative outcome and come back in time and cast a vote, we >> don't have utilities for the counterfactual alternatives. >> >> However attractive it might be to fantasize about functions from cardinal >> utility to social choice, it comes down to an attempt to square a circle or >> invent a perpetual motion machine. The attemp might be fun, but we know a >> priori that it will fail. > > Are we talking about real people or sim people? I think we can make > simulations and models that are useful. Lots of people keep trying, including > me. Or are you sayng that we can't reasonably make sim people whose knowable > sim qualities bear any useful resemblance to the real world? We're talking > about all kinds of mathematical properties of election methods, why not > various measures under stochastic test? What would be a good measure?
I agree that simulations can give us insight into the nature of voting system. It's the translation of those result to real elections that I object to. The sim voter can be interesting in the model without remotely resembling any real voter. (And I don't believe Arrow was mistaken. He was talking about real-world social choices, not models.) ---- Election-Methods mailing list - see http://electorama.com/em for list info
