Ratemyprofessors.com allows students to grade a professor's clarity, helpfulness, ease and - just for fun - rate their appearance as "hot" or "not". A professor with more hot than not votes is awarded a chili pepper on the ratemyprofessors.com web site.
Hotness declines with age, but how quickly? To find out, I combined ratemyprofessors hotness scores with information on when professors acquired their PhD - the best available measure of a professor's age (this information was gathered jointly with my co-author, Anindya Sen, and his co-authors).
The locally weighted smoothed scatterplot (lowess) line above shows that a male economics professor's hotness peaks shortly after he has completed his PhD, and declines steadily from there. An ordinary least squares regression on the 306 male Ontario economics professors in our sample finds that the relationship between years since PhD and hotness is statistically significant: a male professor's probability of being rated hot by his students falls by 0.5 percentage points with each passing year (p=0.003 - the same results are obtained by a probit analysis).
The relationship between hotness and age for female professors appears, at first glance, to be similar to the male graph:
Look closely, however, at the horizontal and vertical axes. At a young age, female professors get relatively high marks for hotness. Reading through the comments, it seems students evaluate such professors in part, on their physical appearance, with occasional comments along the lines of "Wears sexy skirts but terrible prof". In contrast, junior male professors are more likely to get comments like "the best teacher I have ever had, he's just so silly and great. I love him!"
Given the greater weight placed on women's physical appearance, one would expect female hotness to fall relatively steeply with age. Indeed, the lowess graphs above show a steeper drop off for women than for men, but it is hard to see this, because the horizontal axis on the male graph is more compressed.
A probit regression of hotness on years since PhD suggests that each additional year reduces a female professor's probability of being rated as hot by 1 percentage point, however with a sample size of 77 individuals, and p=0.156, the results fall short of statistical significance [I was able to regain significance, however, by dropping one older female professor, whose chili pepper seems to have disappeared since the data was gathered.]
The female professors who are still hot over the age of 50 tend to be outstanding instructors. For example, one gets this rave review "Totally love this prof. She's the most challenging prof ever. She will push and push you to become an active student..." Quality teaching and engagement with students come through in the reviews of hot older male professors as well. For example, one is described as "a pillar of authority, credibility and respectability." However older male professors have been known to get positive comments on their physical appearance along the lines of "Looks a bit like Tim Robbins."
Some might question the intellectual value of an analysis of hotness, and point out that sites like ratemyprofessors, where students can post anonymous degrading remarks, contribute to the challenges young scholars face. Is this post any better than the threads discussing the hotness of various female (and sometimes male) economists on www.econjobrumors.com?
The fact of the matter is, universities are in the business of serving students, and students care. They're spending hours looking at a professor, and appreciate anything that makes those hours more enjoyable. Students believe they learn more from professors who are likeable, good-looking, well-dressed, and approachable.
Some economics professors try to signal their brilliance by following Ariel Rubinstein's advice and wearing jeans and a t-shirt. Do student fail to get the message, and think the professor is simply scruffy or indifferent? I've looked up the ratemyprofessors evaluations of some male economists who are rarely seen wearing anything but jeans, and students don't seem to mention dress sense as an issue, so it's hard to know.
With increasing competition from on-line education and greater demands from the public for accountability, universities are facing pressure to step up their game. Since it's hard to measure how much students actually learn in university, I believe we will see an increasing focus on metrics such a student satisfaction. To the extent that professorial hotness is correlated with student satisfaction, it is useful to understand how it is generated.