I want to respond to some of the comments on my blog regarding whether part of the ideological difference between liberals and conservatives can be explained by their differing estimations of the elasticity of various curves.
First, Thom reminds us of Posner’s idea that the difference between liberals and conservatives is that liberals think that people are selfless but stupid whereas conservatives think that people selfish but smart. This idea is closely related to the one I proposed. For, if people are selfish but smart, then when the price of something rises, they will take note, seek out substitutes, and adjust their behavior accordingly—and hence the demand curve will be elastic. On the other hand, if people are selfless but stupid, when the price of something rises, either they will not notice or else they will be insufficiently self-interested to substitute other products; either way, they pay the higher price, and so the demand curve will be inelastic. Posner’s account, if true, thus plausibly explains why liberals and conservatives would systematically disagree about elasticities.
Second, the liberal-conservative divide over whether a requirement to show identification will discourage many people from voting may well be independent of questions of the elasticity of demand for voting. For example, suppose that, as liberals seem to think, the demand curve here is highly elastic (e.g., say elasticity of 2.0), but that, as the conservatives seem to think, the increase in cost to voters will actually be quite small, say .01%. Then the law requiring voters to show identification would reduce voter turnout by only .02%, i.e., one voter in 5,000. A conservative could then say that this was a reasonable price for us as a society to pay in order to deter vote fraud. I have no idea what the actual numbers are, but it would seem to make sense to lose one legitimate vote in 5,000 in order to preempt, say, one fraudulent vote in 4,000. Even if the percentage of fraudulent votes was less than the percentage of votes lost through the identification system, the gain from people being more confident in the system might make checking identification worthwhile. The defining difference between liberals and conservatives here may thus relate not to elasticities but to the perceived increase in the cost of voting on a percent basis.
Lest anyone be scandalized by the idea that it could be worthwhile to let some legitimate votes be lost, let’s remember that any system at the polling place that limits who can vote, including the present vote, deters some people from voting. It’s only a question of how many lost votes we think acceptable in this context.
Third, I agree with the many readers who said that any explanation of the difference between liberals and conservatives in terms of disagreements about elasticities is partial at best. It explains nothing, for example, about differing attitudes concerning, say, abortion. Differences on life issues, I think, go to differences on fundamental meta-ethical premises. Here, conservatives tend to think that morality is, in some sense, based on a human nature that is shared by all members of the biological species homo sapiens. Since human fetuses or embryos are members of that species as much as anyone else is, they are generally entitled to the same moral protections as anyone else. Liberals, on the other hand, tend to think that morality is, in some sense, based not on human nature per se but on the human capacity for, say, higher mental functions. Hence, members of the human species that are incapable of such functions (e.g., the very young, the severely disabled, etc.) are not generally entitled to the same moral protections that healthy adult human beings are. If some account along these lines is right, then the philosophical differences between liberals and conservatives run very deep indeed.
