Why do people do a postdoc, rather than getting another PhD?

Question

Genuinely curious! From my perspective the postdocs have even less freedom than I do (I work in a national lab, where although I'm a PhD student my experience sadly is more like an employee). I know research fellowships are different, but seeing as most people go PhD -> Postdoc, this to me does not seem like a step forward.

EDIT: I am from the UK, but some of the answers below are about the US. Does seem rather different over there!

They are assigned tasks by our boss, and they have to do them. I remember this postdoc, smart guy, who had an interesting idea but the boss said "sounds interesting but that's not your work" (something he has said to me). Now I can (and have) bent the rules to do more of my own thing. I don't have to come in 9-5 in the same way the postdocs do. So for less research and work freedom they are paid a bit more than me. But after tax, it's not some huge difference?

So why don't we see more people do PhD --> PhD, instead of always PhD --> Postdoc? Seems like the life is better!

Answer 1

Postdoc is a job title that covers a large number of positions and employment conditions.

Some postdocs have significant project flexibility, some are hired to work primarily on a specific project. My postdoc had zero constraints on what projects I pursued, for instance.

Largely speaking, postdoc positions pay substantially more than a PhD. The range I've seen in math in the US is something like 2-3x annual salary increase. This is a very big difference, and taxes don't diminish it substantially.

Departments do not routinely hire PhD holders in nearby disciplines to pursue a second PhD, both because this would be seen as exploitive and because it's a waste of all parties' time.

To put it more shortly: I think you have Dunning-Krugered yourself on this subject. A postdoc is usually the only available full time job type in academia immediately after graduating with a PhD and pays more.

Answer 2

Postdocs are paid 130% to 330% of what PhD students are paid. (This is usually less than what the postdoc could get for a non-academic job.)

Switching to a new university is considered a way to gain valuable experience.

The question and other answers discuss differences in working conditions; I would not generalize about working conditions. These can vary greatly depending on the individual job. Working conditions also vary greatly for undergraduate students and deans.

Answer 3

Many people consider having been formally employed and paid for their work a step forward compared to being a PhD student (who, depending on the country, may not be paid, or may themselves have to pay for the training/tuition). A formal employment allows one to pay taxes, make pension plan, become eligible for mortgage, etc. For researchers from abroad, postdoc employment allows them to get a work visa and years spend doing postdocs count towards their immigration track in the way which PhD career does not.

As for research independence, it's true that postdocs sometimes do not enjoy the degree of academic freedom they deserve. But the same can be said of PhD students, who, depending on their PI and lab customs, may feel micromanaged and overly directed.

Postdoc is a step towards independent (tenured) academic position, which is considered the point when one fully embarks on their own research journey.

Answer 4

Postdoc is the next step in academia, the reason you get a PhD is because:

• you like research
• to get better job prospects.

If you want to do research, then a postdoc is a step which allows you more freedom to research what you want, and (if you're lucky) bring you further along the academia career ladder.

OP, potentially you don't want a postdoc with your current advisor, but that doesn't mean all postdocs will have that problem. Now you know what to look out for in interviews for doing a postdoc. If your problem is with academia in general you can start looking for a regular job

If you are doing a PhD to get a better job, unless the new PhD is in a vastly different area (like one in psychology and another in physics) and your job-to-be is in the new area, there will be close to no difference in job prospects. Or at least not 3-4 years of better prospects.

In that case doing a new PhD will just be wasting time which you could be spending on your career, getting promotions and raises.

In summary, doing a second PhD doesn't help with anything that you would do a PhD for in the first place, be that because you like research, or because you want a better job.

Answer 5

I think part of the issue is the strange set up of (some) PhDs in UK, which tend to be more project-based and time-limited than elsewhere. Nevermind the differences in pay and status, you should after a PhD be research-trained and reasonably independent (in principle at least intellectually although you may still be dependent on local resources and equipment).

As a result, why exactly would you be training for by doing a 2nd PhD? What is the end game here? You could do another PhD or MSc in a different field (some people do this, especially MBA-type degrees) but there is a point where adding degrees does not add to your marketability for would-be employers.

On the other hand, a good postdoc where you demonstrate autonomy beyond your training can be attractive for employers.

Answer 6

Who in their sane senses would put themselves through a second PhD program ?

Even if they were paid 3x what a PhD makes they wouldn't.

PIs are always concerned to keep on schedule with the contracted work and satisfy the supporting client or research council.

Postdocs enjoy several privileges in their department above those of a PhD:

• More regard to their opinion in research group discussions

• Higher priority in regard to access to in-demand lab equipment, high-speed computer time, etc

• More PI access

• Bigger discretionary budget

• Seen by office and university admin staff as a colleague - with associated deference

• Their work hours are - officially at least - as 9 am to 5 pm. => Free to go to Ernie Watts gig in city.

• They often work in close contact with an industry support supervisor, who can later provide a job or very good reference.

• They often are given opportunity to provide some lectures in the area of their research

• Greater freedom to attend seminars in their research topic in other universities - expenses paid

• As staff they enjoy access to staff amenities like sports/gym facilities and possibly also staff health insurance benefits

Once on top of that however it's in PI's and everyone else's interest to consider interesting other ideas thrown up during the program. So your postdoc buddy's idea might be worked on yet.

On research freedom - there is none till the program goals are met or refuted.

On time flexibility - I think this is very dependent on the PI. Some are flexible, some not.

But as employees postdocs are entitled to statutory vacations. PhDs are not, at least officially.

Answer 7

Amassing degrees at the same level of attainment (multiple BSs's, multiple MSc's, multiple PhD's) is frowned upon in many disciplines - even though in particular circumstances an excellent cas9e can be made.

Multiple DSc's is slightly different, since they are obtained in a different manner.

Answer 8

There are other reasons, but even if you look at it from a purely financial point of view the postdoc is a much better option.

My UK-based experience is that my gross starting postdoc salary was roughly 2.5 times my PhD stipend. Once you take off income tax, national insurance and pension contributions, this probably does come down to under 50% extra take-home pay, but...

• Pension contributions are very valuable.
• National insurance contributions also have some value, since they affect future state benefits you may get, including state pension.
• A postdoc salary is subject to annual increments, which PhD stipends aren't. That is, you go up the pay grades in addition to the increases intended to (partially) compensate for inflation.

So really the postdoc salary is worth significantly more.

There is also the question of whether someone who already has a PhD would even be eligible for a PhD stipend. Funding agencies give these out to enable more people to get PhDs. Would they consider one person getting more PhDs good value? I doubt it.