Wednesday, December 12, 2012

Ideal number of PhDs: is it better to die early, or not to be born?

Job market is like weather: not that it changes as frequently, but as weather it makes a nice and safe discussion topic. You met another postdoc, and don't know what to talk about? Just whine together about the bleakness of job opportunities. You'll both get depressed, as a side effect, but at least you'll avoid the awkward silence.

When talking to people, I like asking them about what would they do to improve the academia, if they had the power to do so. Here are the axioms (the rules of the game):
  1. The funding is fixed (increasing funding is an entirely separate topic)
  2. Number of people willing to do science is fixed (it's not actually, but again, for the sake of simplicity)
  3. You want to increase the scientific output (or at least keep it at the current level)
  4. ...while increasing the "average happiness" (whatever it means)
So, what would you do?

Surprisingly, there's no common theme among the answers I receive. The only pattern I could spot is that people generally call for making the bottleneck they have just crossed a bit tighter, while loosing the one they are facing. Thus grad students call for decreasing grad school enrollment, while making graduation more "guaranteed"; postdocs think that "we need fewer PhDs", to reduce competition for the TT positions, and so on. I also follow this pattern by the way.

But this made me think about the "best theoretical solution" to this "bottlenecks distribution" problem. Does it exist at all? If you follow a reductionist approach, and, for the sake of simplicity, concentrate on the "selection process" for future TT faculty, what would be the best "extinction process" to use? If you were the King of NIH, when would you get rid of them lazy bastards, people who will never become PIs? Of all those who foolishly dream of becoming TT faculty, how many would you push out of the system at each respective year of their evolution?

According to my estimations, the current actual "Extinciton chart" for Neuroscience looks somewhat like that:

About 50% of applicants get accepted to grad schools (I assume acceptance rates within each school of ~10%, and each person applying to ~5 schools). 5 years in grad school (I should have assumed more actually); 50% graduate with PhD; then 7 years of post-doc, 20% of postdocs get a TT position.

Is it optimal? Obviously, the answer depends on your definition of "optimal". If you try to increase scientific output (without restructuring job descriptions), you would have to keep them all till the last moment, and then suddenly fire. If you want to decrease spending, you'd have to admit to the grad school only ~5% of applicants, thus making the tenure track more or less guaranteed. If you want "productivity" in terms of "Impact-factor-per-buck", you'll have a complex interplay of different factors, and lots of assumptions about salaries, talent distributions, education investments, etc.

But this dichotomy is obvious. What I find much more interesting is another type of an inherent contradiction here: that between Happiness and Fairness.

The "average happiness among the young folks in academia" would obviously decrease, as you increase the competition at the later stages. If you keep everybody in the system for 15 years, and then perform one giant massacre, people will be extremely unhappy about that. You may think of unhappiness being generated when people are forced to leave academia: the more of their life-time they invested into this thing, the more they sacrificed for it, the more unhappy they will be. Or you may think of it as of frustration that is linearly generated over time, in view of the decimation bottleneck to come. The math is the same in both cases: the earlier you fire people, the less they lose. Thus the system in which only 5% of applicants are accepted into grad schools would produce the most "happy" (in terms of being relaxed) academia.

But this system would also be the least fair one! Because 5% admission at the level of grad school would mean that the admissions would be quite arbitrary. What would you base your decisions on? GPA? Undergraduate education? Scholarships and early publications? All these points would essentially translate into one: "pure luck of being born in a wealthy family with good connections". Older applicants, women with kids, foreigners, lower-class applicants would all be judged against, just because they would be perceived as "more risky" investments.

It is kind of similar to the heritability of IQ issue: the later in life you measure the IQ, the more heritable it becomes. In elementary school kids IQ is almost entirely explained by the environment that is "forced" upon them (bad school, good teacher, etc.), but as we move on, to older subject, IQ gradually starts to become more and more "heritable", with up to ~75% heritability in adults. The common interpretation of this fact is that as you move on, more and more aspects of your life become a result of your personal choice. We all gradually become self-made people, in both good and bad. Granted enough time, we settle kinda where we deserve to be. At the age of 50 your pre-school experiences are largely irrelevant for your success.

And that's why the later you decimate the postdocs - the more fair the system becomes. If a person doesn't have a Nature paper by their 3d postdoc position, it's not just "pure luck" anymore. They had a chance to choose a  grad school; a PI there; and then, say, 3 different labs. They had a chance to either upscale, or downshift. The luck is still important, but while having 1 failed project is quite normal, having 10 of 10 projects failed over a course of 10 years would probably reveal some kind of a pattern.

This being said, if you think that the grad-school-to-postdoc environment is unhappy and depressing, please, do realize that it means that it is at least decently fair. Trying to make everybody in the system "more happy" at the expense of decreasing the in-flow is likely to make the system less fair, less productive, and more frustrating for those worthy people who would be left behind due to their suboptimal early life experiences. Your gambling on your future, and your uncertain career perspectives right now, are a reflection of the fact that you have the liberty, the chance to take a risk. In a no-risk environment, you probably would not had a chance to try.


  1. Interesting thoughts.

    But I actually largely disagree with your analysis of the trade-off fairness vs happiness. There are several issues. First, even if you insist to think in terms of the current US-style system (grad school - postdoc - tenure track), there is a number of things that can be improved. The first thing is that entering graduate students need to be informed about their chances to actually get a tenure track job. It's ridiculous how many entering (and even finishing) PhDs believe that they will get a job. This delusion needs to stop to improve happiness.

    Second, I think the whole system needs to change, even with the current funding. Postdocs should be eliminated and instead permanent _SECURE_ research positions should be established. Research is a job like any other, why is not treated like one?

    Would be happy to discuss elaborated versions of these, perhaps over some tea or dinner :)

  2. 7 years of postdoc? FFS. You folks in life sciences are really brutal to your young...

  3. @GMP: I personally don't mind this part. But I dislike what happens after (and, to some extent, before) that.

    @Sergey: My question was: if you don't restructure the system (end conditions & job descriptions are frozen), but can only play with the dynamics of expulsion - what would the be optimal curve. That's a very narrow question, and not the most useful one indeed =)

    But I'll write about the restructuring as well. Most impact on the system would indeed come through some kind of conceptual reform, not just through "decreasing the number of PhDs" as many people claim.