14

Can you please elaborate on these two tendencies separately? The quotation assumes that your PhD alma mater differs from the university where you first taught. First, why less prestigious than PhD alma mater? Second, why less prestigious than the university of the first teaching position?

In 2005, thanks largely to his field experiments, List was offered a tenured professor position at the University of Chicago, perhaps the most storied economics program in the world. This wasn’t supposed to happen. It is a nearly inexorable law of academia that when a professor lands a tenured job, he does so at an institution less prestigious than the one where he began teaching, and also less prestigious than where he received his Ph.D. John List, meanwhile, was like a salmon who swam downstream to spawn, into the open water. Back in Wisconsin, his family was unimpressed. “They wonder why I’ve failed so miserably,” he says, “why I’m not still in Orlando, where the weather is really great, instead of Chicago, where the crime is really high.”

Dubner, Levitt. SuperFreakonomics: Global Cooling, Patriotic Prostitutes, and Why Suicide Bombers Should Buy Life Insurance (2009). P 118.

  • 1
  • 47
    I think your real problem is you are reading a sloppily written book. – Anonymous Physicist Dec 5 '20 at 8:18
  • 3
    For the tenured job: As a professor (older than a phd student mostly), many other things play a role. Nice living place, love, good public transport etc. often matter (and should matter more) more than uni prestige. – user111388 Dec 5 '20 at 10:34
  • 5
    The university you graduate from is not the complete determinant of your career. What you do in your dissertation and (even more) what you do later is more important. Don't overemphasize any one thing in this, especially in making decisions. – Buffy Dec 5 '20 at 19:51
  • 3
    @gerrit Ha, that’s wishful thinking. There are definitely (vast) differences in prestige between institutes in Europe. – Konrad Rudolph Dec 7 '20 at 13:23
48

Let's pick a real world example. MIT produces around 500 PhD graduates a year. At the same time MIT hires around 50 new professors per year. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4309283/

That means at most 50 MIT PhDs can find a job at MIT. 450 MIT PhDs will have to find a job somewhere else... Which answers your question! Obviously, MIT is not the only prestigious school in the world (or Cambridge, MA for that matter...), but this argument is independent of how many schools are included in the prestigious circle. It all boils down to the fact that (on average) each professor will graduate way more than one PhD student over their lifetime.

This example illustrates what happens in an academic job market in a steady state as is approximately the case at the moment.

  • 5
    Basically correct, but the rate at which professors graduate PhDs does not tell the full story. Hypothetically if the market were expanding r>1 could be OK (such as after World War II). However, I suspect the market is contracting so even r=0.9 might be too much. – emory Dec 5 '20 at 21:44
  • 5
    Very true - I have added a statement about steady state. Incidentally, there is an additional assumption that I totally skipped over. Namely, that PhD holders from more prestigious institutions are likely to outcompete those from lesser institutions. Otherwise the above has no effect! – user2705196 Dec 5 '20 at 22:55
  • 1
    Implicitly assumes that the only desirable job for an MIT PHD is as a faculty member at MIT or other universities. I have worked with many MIT graduates, with extensive research experience and publications, all outside of academia. – RBarryYoung Dec 5 '20 at 22:56
  • 5
    @RBarryYoung I think my implicit assumption was that MIT PhDs aren't less likely to apply for faculty jobs than those from less prestigious institutions. And that they'd outcompute (on average) PhD holders from less prestigious institutions. Which answers the question why it is rare for academic careers to move up in prestige from PhD. I don't think it says that all 500 MIT PhDs have to find faculty jobs or in fact want faculty jobs, just more than 1:10. – user2705196 Dec 5 '20 at 23:05
  • 3
    That brings up the question what the percentage of PhDs from "elite / very prestigious" institutions like MIT or Harvard end up with academic faculty jobs at any institution. The OP's observation would suggests that it is significantly larger than 10% which seems surprisingly high. Now I'm curious! – user2705196 Dec 5 '20 at 23:55
85

This is called the "law of descending prestige."

  • Most universities hire the most prestigious faculty they can.
  • The number of PhDs from the top universities is larger than the number of job openings at universities.
  • Therefore, so long as PhDs seek employment at universities, most of them will get jobs at less prestigious universities than their PhD university.

It is not "inexorable," just probable.

  • 10
    If this is correct, a corollary is that if you got your PhD from a less prestigious university then you have a far lower chance of getting a faculty position anywhere at all. This sounds plausible while also making me sad. – Nathaniel Dec 6 '20 at 1:37
  • 7
    @RBarryYoung: It doesn’t assume those are same — it just assumes they’re significantly correlated, which is surely an uncontroversial observation. (And the correlation can arise through several reasons, some fair and others unfair. Part is the extra perceived prestige of a candidate just from their prestigious background. Part is that prestigious institutions give their students advantages to genuinely achieve more. Part is that prestigious institutions can pre-select more competitively for the most promising students. I think few would dispute that these effects all contribute.) – PLL Dec 6 '20 at 14:32
  • 9
    @RBarryYoung I mean, sure - you could put in all kinds of obvious buts in an answer like this; or you could just assume that a reader understands that Anonymous Physicist is talking about a statistically significant correlation, not a 100% accurate rule. – xLeitix Dec 6 '20 at 22:12
  • 6
    @RBarryYoung "Top universities" is typically defined in part by universities whose PhD students publish the most and best. – Anonymous Physicist Dec 6 '20 at 22:34
  • 6
    @xLeitix. I mean, look at the user name. Of course the answer is talking about spherical universities and point faculty in a vacuum. – Mad Physicist Dec 7 '20 at 9:22
6

Regression toward the mean.

Basically, if you're already at the top, the only place you can go is down. It is well known that over many trials, individuals who perform very well in early trials will tend to perform worse in later ones. This doesn't suggest that the individuals themselves are getting much worse, but instead reflects some aspects of the random nature of success. An illustrative example can be seen in baseball, where players with the highest batting averages in one season tend to have lower batting averages the following season. That doesn't mean that all the top-performing players have all gotten worse; instead it's a reflection of the fact that almost all individuals have worse batting averages than the best averages from any one year. There's some element of random chance in being "the best", and it's simply unlikely to consistently come out on top.

We can view this scenario as a series of trials, where individuals earn their degree, get a professorship, and then become tenured. It's simply unlikely that someone who succeeds at the first step will succeed at all three. Even if you've earned a degree from the top 1% of academic programs, you still have a very low chance of getting a professorship at the top 1% of schools. Unless all graduates of a top 1% school earn a tenured position at a top 1% school, it must be the case that top 1% graduates, on average, get tenured at worse universities. Conversely, if you earn a degree from the bottom 1% of academic programs, practically any professorship you earn will be at a better school.

The overall scarcity of tenured professorships exacerbates this problem, but the phenomenon would likely still exist even if there was a tenured position for every PhD graduate. By chance alone, graduates of "the best" PhD program will become tenured elsewhere that's worse, while graduates of "the worst" PhD program will become tenured somewhere that's better (or not at all).

  • 1
    The problem is that the mean is not having a tenure track job at all. So even the graduates from less prestigious universities tend to move in that direction--not up. – user3067860 Dec 7 '20 at 21:30
  • @user3067860 We do have a confounding effect of survivorship bias - graduates of the lowest-ranked university won't be well-represented among tenured faculty, but those low-ranked individuals that do get such a job would be more likely to get one somewhere better than their alma mater, since most tenured openings are at places better than their alma mater. I agree that the scarcity of tenured positions forces the mean to be "not tenured at all", though, so even graduates of low-ranked universities can do worse in practice. – Nuclear Hoagie Dec 7 '20 at 22:02
3

When you write your PhD, you receive important help and guidance. So it is no proof that you by yourself are capable of something that important. Also, the standards for a PhD, even from a very good university, are not as high. A PhD will be accepted even if it is not a very important contribution to science.

In your first job, you are perhaps still just following the lines of thought you already learned from your teachers and associates at your school. For most researchers, this slowly gets drained and leads to fewer and fewer new results. So, are you one of those few who can continue to learn new important things on your own, when separated from your original teachers? Not so many can!

After a while, if you yourself alone produce results equal to or better than your PhD, if both your PhD and your later self-generated results are way above the average Phd standard, you will be invited back to an equally prestigious school, perhaps.

  • Not sure if this is exactly the answer to OPs question, but the description in your middle paragraph is point on. +1 – Karl Dec 7 '20 at 21:40
1

Large and successful and rich institutions have a lot more assistant professors than can get tenure there. They are hired for their research expertise.

"Rural" universities do a lot more teaching, and sometimes little or no science. If someone got a doctorate there, he's likely to want to go somewhere prestigious afterwards for postdoc and assistant professor. Has to, because the prestigious places have more money and projects to hire him on.

So when tenure positions are open anywhere, the applicants generally come from well known universities.

The specifics vary a lot between countries, of course. The scale from "top" to "rural" is wide and continuous in the US, in Germany you have a hundred full universities, which don't give each other much (some all claim they do), and 300 "Fachhochschulen" where you can't even get a doctorate.

0

Supply and demand. There are way too many phds for the university jobs available. Top schools want top PhDs, And so on down the line, until the excess go teach at a community college or work for the government.