Monday, October 25, 2021

Finally: historical data about US PhD chemists from the Survey of Doctorate Recipients

Via a tweet from Derek Lowe, this very interesting paper by Dr. Stephanie Cheng (a PhD economist), summarizing and extrapolating data from both the Survey of Doctorate Recipients and the Survey of Earned Doctorates. The Survey of Doctorate Recipients is the NSF's routine survey tool to look into the lifetime of doctoral graduates. 

Her paper discusses three results: 

It's taking longer to get out of grad school: "Over the past fifty years, mean time spent in graduate school has steadily increased by 2.2 years, from 5.8 years (s.d. = 2.1) among 1960-1980 STEM Ph.Ds. to 8.0 years (s.d. = 4.1) among 2000-2013 cohorts... Figure 5 demonstrates that fewer individuals are completing Ph.Ds. in fewer than four years and more individuals are completing Ph.Ds. in more than eight years over time."

Fewer people are getting tenure-track positions: "As doctoral training has lengthened and more STEM Ph.Ds. have pursued postdoctoral training, the probability of obtaining an academic tenure-track position has nearly halved over the past fifty years. Only 25.2% of 2000-2013 STEM Ph.D. graduating cohorts are ever observed in a tenure-track position, compared to 42.8% of 1960-1980 cohorts." 

Postdocs cost PhDs lifetime earnings: "To quantify the impact of postdoctoral experience on salary at each career stage, Figure 19 gives salary regression coefficients on years of postdoctoral experience for each of the first thirty years post-Ph.D. graduation, as calculated in Equation 1. The first few years show a large negative relationship due to the salary gap between postdoctoral appointments and permanent positions. This gap closes as postdoctoral researchers move into permanent positions, but the additional training does not improve their salaries enough to overcome this early loss. As given in Equation 2, the average of these yearly coefficients can be interpreted as the postdoctoral deduction in mean lifetime earnings. Rather than provide an education premium, each additional year of postdoctoral experience reduces average lifetime earnings by $3,730."

All three of these results are not new to this discussion, almost to the point that you have to ask yourself "is this news?" And my response is a confident "yes." First, it's documented quite clearly by her analysis of SDR cohorts, and it appears that not many people have decided to do this. Second, she chose chemistry specifically as one of the PhD fields to be analyzed, and so Appendix B has some really nice data to summarize her findings. Of these, I'll choose a few of note: 

  • Between the 1960s and 2013, the mean years in graduate school for chemists had moved from slightly less than than 5 to slightly less than 7. 
  • The number of PhD chemists who took 4 years or less dropped from 40% in the 1960s to less than 10%. Meanwhile, the number who took 6 years rose from 10% to 30%. 
  • The percentage of PhD chemists since the 1980s who did a postdoc within 2 years of graduating has never been lower than 40%. 
  • The percentage of chemistry postdocs who did a 1-2 year postdoc fell around the time of the Great Recession from 30% to 20%, while those who did a 3-4 year postdoc rose from 10% to 30%. 
  • The percentage of PhD chemist cohorts that had a tenure-track position at anytime went from 36% in the 1960s to 10% in 2013. 
  • Since 1972, the modal outcome for a PhD in chemistry 10 years after graduate was a position in industry, from a high of ~60% to a low of ~42%. 
I will end on a tiny bit of a triumphalist note. I have been banging on for a number of years about how we have a paucity of data about both the past and present of the chemistry jobs market. Dr. Cheng has done us a huge favor by providing some of it. Instead of arguments about what is and is not "traditional", Figure B.9 provides us data and tells us what was traditional from 1970 until 2010, and what I strongly suspect is still traditional today: most PhD chemists end up in industry (~40%), some have a tenure-track academic position (~20%), some work in other academic functions not on the tenure-track (~19%) and some work in non-profit or governmental settings (~19%). 

I think this paper confirms my biases is likely to be right, and the only way to figure it out is to find data to either back it up, or contradict it. Dr. Cheng has gotten us started, and we'll have to do the rest ourselves. Let's get to it. 

20 comments:

  1. One of my undergrad professors started her job at age 25 in the late 90s after a 4-year PhD and no postdoc. I would guess there's no such thing as a 25-year-old professor today.

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    1. So the Survey of Earned Doctorates indicates that there are ~100-200 people who get academic jobs immediately post-PhD (124 for 2019). You can see in the Faculty List that many small college openings are looking for someone immediately out of grad school and they're willing to consider students who have not defended as potential candidates. I imagine the number of sub-4 PhDs is quite low, but that the number of sub-5 PhDs is not zero either, so that would get you a 27 year old professor (which seems pretty young!)

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    2. Perhaps you forgot about Phil Baran. But he also graduated undergrad at age 20 IIRC and had an offer at Scripps directly out of a 4yr PhD but still chose to do a postdoc with Corey for 1-2 years. So I think he started out as a prof at around age 25-26 in 2003.

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    3. confirmed - Phil Baran's DOB is August 10 1977, which makes his start at Scripps in June 2003 at 25. https://www.scripps.edu/baran/images/baranCV.pdf

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    4. Thanks CJ. So he could have potentially been an asst prof at scripps at age 23 in 2001. Incredible.

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  2. I have to thank chemjobber to get me into the habit of following the earned doctorate survey every year - I see a trend of more chem phds graduated (from less than 2k some years ago to on the way to 3k now?) while less jobs are on the market. I mean, 2k chem graduates vs. 500ish faculty position isnt heading at the right direction.

    I was more interested in the career part of the survey, and my finding is - any major with the word bio in it suffers a huge cut in industry employment, bio-chem, bio-life science, bio-engineering, you name it - you'd typically see >50% industry employment in any engineering discipline until bio-engineering, then its damned to ~25%. Too many bio-related majors go for postdocs (60% if i remember correctly?) and unfortunately chem is following bio's footsteps.

    from the limited sample size of my grad school cohort, I think 4 people got faculty/visiting professor/lecturer position, all at PUI though. some kids went for industry but most stayed in academia via postdocs. Interestingly all people from my lab that I know went to industry without looking back - imo we would all tank in academia anyways.

    Although this habit did lose me a pointless internet gamble from dr. hansen's stream some wednesdays ago - apparently there are only <3k chem phds awarded globally in 2015, while US probably did half of them...

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  3. I think the two alarming statistics to me were:
    -The percentage of PhD chemist cohorts that had a tenure-track position at anytime went from 36% in the 1960s to 10% in 2013.
    -Since 1972, the modal outcome for a PhD in chemistry 10 years after graduate was a position in industry, from a high of ~60% to a low of ~42%.

    Just overall less job opportunities for chemists in both Academia and Industry. I've spoken with a few older chemical industry people in the specialty chemicals space and they have also told me that business units that once used to employ 20-30 chemists with PhDs or BSs to support a $6 billion dollar business 20 years ago might now only employ a handful of people.

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    1. I'm not ready to hang my hat on the 36% to 10% drop for T/T positions. There is a downward trend, but this drop seems too extreme. I think there is a lag effect as people are doing more and longer postdocs, and would expect the last few years on the chart to continue increasing.

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    2. im not so surprised; from a really rough estimation in figure 1 (# of ppl in each cohort) in 1960 it looks like that number is ~200, where in 2013 it looks like ~1600 (which is what i remembered from the NSF survey, <2000; not sure where the 4k+ numbers in 2010s comes from, that sounds outrageous). # of TT jobs in recent years on the other hand is an easy one from this blog: about 500. then you cut it by half since not all of these jobs posted want freshly minted phds, then 10% of phd chemists in each cohort get TT positions sounds about right?

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    3. remember figure 1 in the paper is more than just chemists re: 4k+

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    4. It took me too long to find this, but C&E's starting salaries survey ( https://cen.acs.org/articles/89/i11/Starting-Salaries.html and pdf link [addn'l tables] https://pubs.acs.org/doi/pdf/10.1021/cen-v089n011.p049 ) must have some level of data that can be applied to this problem. Survey by G. S. Edwards and J. R. Allum.

      Raw numbers: "... 10,268 recent graduates were sent surveys, and a total of 2,429 usable responses were returned, a 24% response rate." It's unclear though what range of years are inclusive of "recent graduates," but there must be a by year number somewhere in their survey that would enable the breakdown of cohort size by year. They have some additional numbers in there (page 4 of pdf) showing that 60% (?!) of PhD chemists are employed in academia. I assume this is T/T, R/T and postdoc, but without a better number breakdown it is hard to figure.

      Applying the 2000 PhDs/year (where did this come from?) and 500 jobs/year (Ref CJ) gives 25% of each cohort an academic job (assuming over a long enough time period each equalizes from uneven postdoc length). This figure seems to match the current Cheng paper (ty for the find CJ), at least up to ~2007. From that, I think the 2008- numbers will filter up as people finish postdocs or transition back into academics from industry. I think there's still a downward trend, but still 20+%, not 10%.

      By that math, the academic path doesn't seem so bad provided you're willing to tolerate a lot of postdoc. If half your cohort initially pursues something else, you need to be in the top half of the remaining 50% to eventually get some sort of academic job. Loss of earnings, not getting that job, and perpetual stress, notwithstanding.

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    5. 2000 PhDs/year is a rule of thumb-ish for the Survey of Earned Doctorates number for graduating PhD chemists in the US per year.

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    6. 2019 number: 2941 (2019 SED table 59)
      2020 number: 2763 (2020 SED table 59)

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  4. This thread is proof positive that pursuing a PhD in chemistry nowadays has become an extraordinarily risky proposition with low potential of reward. Longer and longer times in graduate school and postdoc, the path to tenure-track positions growing even bleaker, as well as continual contraction of the pharmaceutical industry since 2006 makes continuing employment as a chemist virtually impossible. One has to ask why the professional societies and academia continue to beat the drum that we need more chemistry PhDs when every possible metric indicates that the job market for chemists has been in contraction since the early 2000s and the opportunities for tenure track jobs continue to shrink. There are still far too many people getting mediocre doctorates and then can't compete in either the academic or industrial job market. Due to the factors discussed above and an absolutely saturated job market, unless you have amazing connections or are in the top 5-10% of chemistry PhD grads - I can't recommend chemistry as a career nowadays. You are so much better suited getting a business, medical or engineering degree and getting into the workplace while you are in your early to mid 20s.

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    1. [citations needed] for some of these assertions

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    2. Professional societies are reliant on their membership ranks being filled and dues being paid. Should be a good indicator as to why they advocate for more PhDs. Further, the research done by PhDs in all chemical endeavors is in some way quite valuable to society. It might seem bleak for job prospects right now and for the future, but I suspect a measurable percentage of PhD research gets converted into a start-up, which creates jobs/value for all of us. After spending 5+ years as an industrial polymer chemist I am actually interested in going to a start-up at some point in my career to try and launch something big.

      For those who are going to go to graduate school though I suspect that the data around what they will do afterwards should be given to students before they embark on the higher degree journey.

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    3. My own experience as an industrial chemist with a MS has been that almost everywhere I worked, I needed better managerial and people skills to aspire to my boss's job, not better scientific skills. After a few decades in industry, I'm convinced that there's a huge oversupply of scientific talent, and an ambitious young person would be better off following a BS in chemistry with an MBA to go after positions at higher levels of responsibility. Companies doing fundamental research like DuPont, Rohm and Haas, Union Carbide, and the old pharmas just plain don't exist anymore, and it's more likely you'll be working somewhere that needs great managers with good-enough scientific skills rather than great scientists with good-enough managerial skills.

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    4. Great formulation: "it's more likely you'll be working somewhere that needs great managers with good-enough scientific skills rather than great scientists with good-enough managerial skills."

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  5. It seems like the term "industry" can be a gray area, when you look at only academic vs industry. There are many fields, such as science communication or the business side of pharma, that employ PhDs, but may or may not get classified strictly as "industry", depending on the survey.

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  6. I don't see anything in this survey regarding PhDs employed in industry but working outside their field of study. Except for one, all the people in my field that I went to school with have industry jobs way outside their original field of study and several (including me) had to go back and take classes/earn certificates/get masters in other fields so that we could be employable. Most of us left the ACS when we were unemployed or not going to their conferences so all of us chemistry dropouts aren't tracked. If I could do things over, I wouldn't get a phd in chemistry.

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looks like Blogger doesn't work with anonymous comments from Chrome browsers at the moment - works in Microsoft Edge, or from Chrome with a Blogger account - sorry! CJ 3/21/20