Who needs Pop Psychology when you've got Pop Economics?

It looks like (mangled) concepts from economics and game theory are set to take over from pop psychology as the rushed journalists' choice to explain social phenomena. Besides the advantage that economics is more en vogue than psychology these days, sounding more logical and, um, hygienic (no messing around with sexual issues and being badly treated by your mom), it has the added advantage of allowing the journalist to link to incomprehensibly mathematical papers as reference, so it becomes difficult for readers to call their bluff. Take, for example, this article on Slate (linked to by both MR and SM), which tries to explain 'The Eligible Bachelor Paradox', using economics and game theory to 'explain the shortage of available, appealing men'.

You can think of this traditional concept of the search for marriage partners as a kind of an auction. In this auction, some women will be more confident of their prospects, others less so. In game-theory terms, you would call the first group "strong bidders" and the second "weak bidders." Your first thought might be that the "strong bidders"—women who (whether because of looks, social ability, or any other reason) are conventionally deemed more of a catch—would consistently win this kind of auction.

But this is not true. In fact, game theory predicts, and empirical studies of auctions bear out, that auctions will often be won by "weak" bidders, who know that they can be outbid and so bid more aggressively, while the "strong" bidders will hold out for a really great deal...

Where have all the most appealing men gone? Married young, most of them—and sometimes to women whose most salient characteristic was not their beauty, or passion, or intellect, but their decisiveness.

All of this sounds great, except that there's very little related to auction theory in there, especially if you were to go through the paper the author links to. In fact, while the paper does talk of the weak bidders bidding aggressively, that's in the context of bid shaving - bidding less than their total holdings. In effect they're driving a tougher deal with the seller, not settling quickly. Overall, it's a lot of faff dressed up as game theory - after all, just because some women are 'easy', doesn't mean men have to get married to them. Indeed, there's absolutely no discussion of the men's preferences. But I guess it's written to appeal to single, lonely women who read Slate and have a higher opinion of their intelligence, to make them feel better about not finding an eligible bachelor yet. The women who've found guys are all probably too busy to read Slate - the hussies.
But I come to join the ranks of pop economists, not to bury them. So here's my take on the same problem, using good old-fashioned Consumer demand theory and indifference curves.
To begin with, let's start with a utility function describing the preferences of a man over Intelligence and Beauty:

U=U(I,B)

i.e. the individual gets utility from (his partner's) intelligence and beauty, and aims to find a partner with the optimal combination of both (assuming convex preferences). The indifference curves would be as given at right.

For this particular model , let's consider the individual's endowment to be in terms of time, which constrains his ability to choose. The budget constraint can be written as

M=P1I + P2B

Where M is the time available, P1 is the 'price' of intelligence - interpreted as the time spent to search/identify intelligence. Similarly P2 can be considered the 'price' of beauty (given that it's easier to identify beauty, P2 would be less than P1, with the slope of the budget constraint, (-)P1/P2 >1). The budget constraint for one endowment is shown in the diagram as M1, with the individual choosing the combination (that is, partner) A.
Now consider that it's becoming easier for women to look pretty these days - better make-up, shampoos, hair irons and what-have-you, which means that the 'supply' of beauty has gone up, which in turn means the price has gone down-with more pretty women around, the individual has to spend less time to find them. This change in price will affect the final outcome, which can be split into the substitution and income effects.
The (Hicks) substitution effect is the effect of the individual changing his choice, given the new prices, if he had to stay on the same indifference curve - i.e. get the same level of utility, for which he would in fact require only an endowment M1'. This would see him shift from combination A to combination A', opting for a greater level of beauty and substituting away from intelligence.
The change in prices also implies an increase in purchasing power, which is captured by the income effect. The individual's new budget constraint is M2, putting him on a higher indifference curve (i.e. getting a higher level of utility), and his final choice will be the combination B, with greater beauty and less intelligence. (if we considered beauty to be an inferior good, we might have expected the income effect to counter-act the substitution effect to some extent, but, hey, that's not realistic now is it?).
In a nut-shell, that means that as it becomes easier for women to look pretty, men would readily substitute away from intelligence and opt for a partner with greater beauty. And we didn't even need auction theory to explain that.
But we might as well ask what this means for the intelligent, single women who read Slate magazine. One option is to go out there and get themselves noticed - that would reduce the 'price' of finding them, which should cause the price effect discussed above to work in their favour. The other option is to pretty themselves up - that moves them up to a higher indifference curve, and thus more desirable. Of course, both options are not mutually exclusive.
So there you have it, all you intelligent, single women, your prescription for relationship success: look good and get out there.
Hooray for Pop Economics!