After a PhD, why do people generally do postdocs at universities rather than work in research firms or organizations?
Is it only because they want to become academicians?
After a PhD, why do people generally do postdocs at universities rather than work in research firms or organizations?
Is it only because they want to become academicians?
Unlike the answer of lordy I need to mention something less positive.
In today's academic market, people do postdocs because they have no other good option if they want an academic career. A tenure track position would be the far better choice if it were only open. But, currently and recently, there have been too many people seeking too few regular positions. Therefore people take postdocs to try to get into a better position for a regular position. Or, simply to hang on for a few years.
Long ago, when I was a student, this wasn't the norm. There were very few postdocs and people usually moved from a doctoral program to a tenure-able position if they had any promise. I knew only one in a faculty of about fifty (with three times that many doctoral students). And even his case was special in some ways. The marketplace for faculty was very different.
Now, however, if you want to move from being a student to being a professor, a postdoc is considered essential since the old pathway is no longer as open as it once was.
Note that (US perspective), the Assistant Professorship was designed to be a fairly long (typically seven year) probationary period in which candidates can prove themselves in ways important to the institution, usually Research, Teaching, and Service. Now, however, it has become a 9 or more year process in which you have to prove yourself before you even get a chance to prove yourself.
I consider this a step backwards, because of the risk it puts on people, but I have no solution, other than massive influxes of money into education. That would be a good thing, IMO, but isn't likely.
Trying to use a research firm as a "fill in" to an academic career is very unlikely to be successful today, since very few firms do pure research as opposed to product oriented research. There are a few, but not many, and they are focused on only a few fields. Even a research slot at IBM is unlikely to bring you back to academia. Google, perhaps, but not many.
Another positive reason for doing a postdoc is simply that you love your subject and enjoy doing self-directed research.
As a student, you may have coursework as well as research. You are also more likely to be carefully directed by your supervisor. And above all else, you don't necessarily yet have the skills or experience to explore all the avenues you'd like to.
At a company, your work has to be focused towards the priorities of the company. Different companies will allow different amounts of freedom of direction to their employees, but at the end of the day, you need to be solving problems that are relevant to your employer.
As a professor you've got to worry about teaching, admin, committees, securing funding, supervision of students and postdocs etc. Actually doing research is rare as a tenure or tenure-track faculty, at least in experimental subjects.
In many ways postdoc is a golden mean - your are experienced and qualified enough to follow your ideas, but not encumbered by all the responsibility that comes later. You can come in each day, sit and your bench/desk/computer and just do the research you want to do.
There are several reasons to do a postdoc:
Generally doing a postdoc if one is not pursuing an academic career doesn't make very much sense (with rare exceptions). Especially if someone is doing a lot of consecutive postdocs the CV might even look a bit desperate and might even lower employability in industry.
EDIT: As pointed out by buffy below the chances of actually getting from a postdoc into a permanent academic position are rather slim nowadays. This is why I wrote "higher success rates for more senior academic positions" which in turn does not necessarily mean that you will have success.
I'm going to copy and paraphrase from my answer here:
Because it's fun!
I did a PhD because it was fun, and I wasn't ready to quit after my PhD. By doing postdocs, I had the opportunity to spend time in various different countries around the world. A postdoc is not only an opportunity for another job that is more or less 100% research, but may also be another chance to explore the world. Want to spend 2–4 years in Japan, Australia, Spain, Canada, or Argentina? If the right postdoc opens up, here is your chance. Where visas are needed, they may be easier to get for temporary positions than permanent ones (US example J-1 vs. H-1B). Going into a permanent position and leaving after 2–4 years may be not appreciated, but for a postdoc it is expected. And the privileges of a PhD position apply too: do what you love, and with some luck getting paid for conference travel to amazing locations you would otherwise never visit.
If you want to postpone growing up a bit longer beyond doing the PhD, postdocs offer you the opportunity.
The other reason is that I wanted to do research, and almost all research positions are temporary, thus either actual post-doctoral positions, or post-docs in all but name.
After a PhD, why do people generally do postdocs at universities rather than work in research firms or organizations?
I disagree with this premise, albeit with a sample size of 1. However, you question shows that many grad students do not know about non-academic research opportunities.
Many people such a myself do a postdoc working for a government research agency. Likewise, I know people who have done industry post docs. These post docs allow us to obtain the skills, credentials, and other background necessary to be research scientists.
Is it only because they want to become academicians?
Nope, many non-academic research jobs require research experience after a PhD to be qualified to lead large research projects.
Also, it's worth noting that government and industry post docs pay well compared to academic post docs. For example, I got full US Federal employee befits during my post doc as well as time in service for retirement benefits.
Edit: This is field specific, but examples exist across many fields. Here are examples of different non-academic positions:
These examples show how non-academic postdocs may be helpful for some people, given their career goals. But, if one does not want to lead a research group, they probably do not need a postdoc
Edit number 2: Given a recent Nature News career article, it looks like many people are not doing a post-doc. Basically, the job market has changed such at people can go straight to industry and do not need a post doc. And, more people do not see the appeal of an academic job that requires a post doc.
Thus, to re-answer your question:
After a PhD, why do people generally do postdocs at universities rather than work in research firms or organizations?
People increasingly are not doing postdocs at universities. Please see my linked article for why.
If you want to keep doing research in your field then you will quite often have to do postdocs. That's because these other research positions will ask for postdoc experience (or things that are effectively postdoc experience, such as "proven track record of publications in top venues").
Another reason is that the kind of work you want to do might not be available at industry research positions, because the funding system is different. It's not always the case, but especially in the commercial world, you might be asked to work only on things that are related to the company's products.
To stay in the US, though it depends on who you are are talking about.
I'm in the US, and many of my friends and acquaintances are foreign post-doc students.
I would not be surprised if 9 in 10 of them, when asked why they continue their studies, would say, "to stay in the US", despite often severe burnout or low pay.
Many of them, despite years of academic experience and post-doc or multiple PhDs, are in, incredibly, precarious visa situations that prevent them from taking private sector jobs, and the last thing they want is to have to go back to, say, Iran or Vietnam, possibly for good. Staying in academia means keeping one's visa.
There are very few firms offering post-docs in mathematics. Moreover, postdoc at universities offers teaching experience, which is very valuable if one wants a position in academia later.
I'd like to chime in with @gerrit, but I personally disagree with the growing up (or not) aspect both in gerrit's and some other answers. To me, a postdoc is not about growing up (and much less about postponing to grow up):
When I was a fresh PhD student, on some occasion my professor made me realize that with my graduation (Diplom back then, before I started the PhD) came the full professional rights and duties.
I decided to adhere to that perspective: Diplom (or Master) means fully qualified professional. Not (yet) much experience or seniority, but definitively "professional adulthood".
The qualification "argument" IMHO is just a try at subduing people (e.g. wrt. wage level, [micro]management). Employers do this all over the world, just the mechanisms may be a bit different between industry and academia. But I definitively recommend to be grown up and take your stand there as academic postdoc the same as if you were in industry with the same amount of professional experience.
I did a bunch of postdocs*, and to me that was always working in my profession. In contrast, the next step in an academic career, becoming group leader, would have meant to change profession, at least partially, from researcher to manager. There is nothing wrong with doing this (I also teach, which I also count as another profession), but IMHO it's good to be aware of what is happening and to consciously decide what one wants to do professionally.
Colleagues did the step to manager without being aware, and found themselves being almost completely manager. Some have explicitly told me that they strongly miss doing research since managing research is not the same.
I also think that from a macroeconomic perspective the "prescribed" academic career (postdocs should go on to be group leaders) is a huge waste: the transition occurs roughly at a point where researchers have gained sufficient experience to become really efficient in their research profession. And then they go and become inexperienced (and untrained) managers...
So, one reason for "staying" postdoc is wanting to do research, together with the practical consideration that such a suitable position is available at what happens to be an academic institution (rather than industry or other organisation).
*postdoc as in being researcher on a project (with fixed time contract)
I did 2 years of post-doc because it was the first form of employment I found after my PhD. I was hoping to be an academic, but prof jobs are fewer than PhDs. At least in my subject area. So, after 2 years, I went outside academe.
I knew a guy who was basically a permanent post-doc. He was in his late 40s, and there was no way he would ever be a prof. But he knew enough about his areas of study to keep getting contract work with profs in the department. And he was prepared to do teaching and mark papers and such. He got papers published regularly in collab with several profs in the department. And he seemed to be accepting of the level of income, which was substantially less than even a junior prof. It was not a situation I could have lived with, but he seemed to find it to be OK.
You've asked a very good question which reminded me of several issues in academia very close to heart. There are lots of good answers here already. I would say the reason most PhDs do postdoc is because this is really the most readily available route to progressing their academic careers. As with most things in life, there are pros and cons of doing postdocs.
Pros
Cons
Myself and my wife are both PhDs who have decided not to go down the postdoc route. We both genuinely love research and academia. My wife is a PhD in STEM who managed to get into a research role with a large institute of research (UK). I am fortunate enough to have a clinical career alongside my academic career which pays a lot more income and has the stability that postdocs lack. I have continued to do research in my own free time publishing when I can. Ideally, I would like to spend more time doing research but the low income and lack of career structure deters me from taking up a full time role in research. I have a young family too and having a career with stable income is very important to me at this stage of life. I really feel academics deserve better and a clearer career path will attract more talents.
In summary, yes most PhDs do postdocs but there are a number of PhDs who have also gone down non-postdoc routes.
I'd say the reason is that they enjoy studying and enjoyed their degree and they would like to further it and "they want to study m0re".