Gentlemen Prefer Dumbs

A few days ago, during a nice dinner at The Vaults, two friends of mine, let's call them K and M, an economist and an anthropologist respectively, and myself, we were talking about the possible effects of the economic crisis on the marriage market. At some point we discussed whether the crisis was going to alter in any way the assortative matching that typically arises in that market. From your own experience, you should have noticed that people tend to match with people of roughly their same socioeconomic status and/or physical attractiveness. The explanation is simple. Suppose that the value of a person can be measured in a universal scale, like the genetic fitness of their potential offspring or the resources they can provide to that offspring. Suppose also, for the sake of the argument, that there is the same number of people in each side of the marriage market. Therefore, everybody in one side of the market (let's say the males) share exactly the same preferences over potential partners, and the same happens in the other side (i.e., the female side). If that is the case, the only pairwise stable matching is assortative: the best male matches with the best female, the second best male with the second best female, and so on. Suppose that that were not the case. It would imply that at least one person in each side of the market is matched with someone with a lower ranking that him/herself. These two "unhappy" people could improve their situation by breaking their previous match and being together.

Then my anthropologist friend M raised a question: We observe that males tend to go for females that are not more intelligent or successful than themselves. Why? After acknowledging that there was a certain truth in that, K and I looked for an answer. The simplistic model of matching that I proposed above assumes that females will have offspring for sure. But that may not be the case in reality. More successful and intelligent women will typically have better outside options to childbearing so they are less likely to agree to reproduce. So if that probability is Pi and the value of female's i offspring is Qi, the value of matching with that female is just PiQi. Hence when going for more intelligent females, men may be trading off higher quality offspring with a lower probability of reproduction. Notice that the same argument applies if Pi represents the men bargaining power within the household against female i and Qi is the quality of the relationship or a measure of some other type of investment made by the female. This assumption can be enough to generate a non-assortative matching in which men have a positive optimal level of female “dumbness." And implies, if we maintain the assumption of equal number of males and females, that that some very intelligent and successful females may remain unmatched.

The moral of the story for you should be that we can try to apply that economic thinking to shed light on any question, phenomenon or puzzle you may encounter. And also that we have lot to learn from listening to other disciplines. That is, unless you are too busy chasing a dumb enough partner out there.