Thursday, October 20, 2005

The Slide Rules of Attraction

Broadly speaking, physical attractiveness has two sources. The first is innate beauty, generally arising from one’s genetic endowment. The other is external effort, in the form of exercise, good make-up, fashionable clothing. A person’s observed level of attractiveness is some function of both. So here’s the natural question, from an economic perspective: are innate beauty and external effort technical complements or technical substitutes?

If they are complements, having more of one should increase the return on the other. If they are substitutes, having more of one should decrease the return on the other. For example, for whom would a professional make-up job make the greatest difference – a beautiful woman or a homely woman? Say the make-up job turns the natural 8 into a 8.5, and the natural 4 into a 6. In that case, the homely woman benefits more (assuming a uniform attractiveness scale), and thus innate beauty and external effort are substitutes. The make-up makes up for what the homely woman doesn’t have, whereas its impact is more superfluous on the beauty. But if the make-up job turns the natural 8 into a 9.5 and the natural 4 into a 4.5, innate beauty and external effort are complements. The make-up can only enhance what’s already there.

Why does it matter? Because the answer will affect the distribution of attractiveness in the population. From a given initial distribution, based on innate beauty, complementarity will tend to spread the distribution wider. The natural beauties will find it worthwhile to make themselves yet more beautiful, while the less fortunately endowed will make less effort and allow themselves to go downhill. Substitutability, on the other hand, will tend to narrow the distribution, as those endowed with less natural beauty will work harder and thus narrow the gap. A question for readers: based on your observations, which is closer to the truth? Does the answer depend on the gender in question?

Most changes occur on the external effort margin. But we can imagine some changes on the innate beauty margin. Someone who suffers a disfiguring accident takes a negative shock to their innate beauty. And while plastic surgery might seem the most extreme version of external effort, in this context it is best seen as an attempt to enhance innate beauty (since plastic surgery does not require ongoing effort, but instead changes the baseline to which ongoing effort adds). These cases could provide potential tests of complementarity versus substitutability. To the extent the inputs are complements, the disfigured person should make less deliberate effort than before, the plastic surgery patient more than before. With substitutes, the reverse would be true.

If the rewards of attractiveness depend not merely on one’s own realized attractiveness but also on that of others, then strategic concerns come to the fore. But those will have to wait for a future post.

(Aside for serious econ nerds: In mathematical terms, the key figure is the cross-partial derivative, which shows how a change in one variable [natural beauty] changes the effect a change in another variable [external effort]. If the cross-partial derivative is positive, then greater natural beauty increases the return on external effort, so the inputs are technical complements. If the cross-partial derivative is negative, then greater natural beauty diminishes the return on external effort, so the inputs are technical substitutes.)


Jeff Brown said...


“Ugly people will tend to look somewhat like clowns with makeup.”

If so, why would they use makeup?

I would assume that one gets better at using makeup with experience and that the better you are, the harder your makeup is to detect. Since most people who wear makeup have done so for a long time, it seems likely that most of it’s hard to notice.

“It has been proven that regular shape is generally more attractive than body characteristics that differ from the norm.”

When I go to the gym and I see someone exceptionally fit, I inevitably think they’re exceptionally good looking. Only in magazines have I seen people with so much muscle that it seems to detract from their appearance. I had thought my preferences were normal, but maybe they’re not.

MT said...

Neat idea to apply economic methodology this way, but I'm skeptical. We don't only make money by our looks, but also mate (notice how lots of us go to pot when we marry or find a steady partner?) and make friends (notice how all the people living together on Friends are good looking and stylish?). I wonder whether a graph of different occupations would show a linear trend of higher standard pay for a higher likelihood of the job being occupied by "a looker"--or if the average attractiveness of people in a given occupation correlates well with how much the occupation tends to pay. I kinda doubt it. I bet looks help you succeed in your job (e.g whether you get moved to the New York office and earn New York pay, whether you get promoted) and certainly they play some role in the kind of job you'll get (e.g. radio vs. TV, receptionist vs. clerk), but it doesn't look like a simple role and not one I'd expect to correlate simply with the salaries that such jobs pay.

Blar said...

BBC says substitute, at least for make-up:

Both male and female volunteers rated the faces of the women with the highest hormone levels as the most attractive.

These faces tended to have classically feminine features, such as larger eyes and lips and smaller noses and jaws.

However, when the women in the photographs were wearing make-up, no relationship between attractiveness and oestrogen was found.

Glen Whitman said...

Thanks, Blar -- I'm blogging on it now.