Post-Docs: Academia's Miserable Waiting Room
Congratulations, you just earned your science PhD! Are you headed into the world of private employment? Bully for you: you can expect to immediately earn a higher salary, likely receive more lifetime income, enjoy better benefits, and experience vastly greater job stability upon leaving the academic fold.
Do you want to continue searching for new knowledge and striving to advance your research field? Sincerely speaking, is your ultimate career goal to land a vaunted slot as a tenured university research professor? Your new reality is comparatively grim: post-doctoral ("post-doc") appointments.
A post-doc is a position that is all of these things: temporary, usually necessitating a cross-country move, extremely demanding, and extremely low-paying. A post-doc is typically hired for a term of one to three years and paid somewhere between one-half and one-third of the salary that he or she could make outside of academia. Job openings are scattered across the continent.
PhDs continuing in academia generally take two or more of these appointments. They work and wait for their chance at a faculty job that includes a shot at tenure -- the so-called tenure-track position. A strong majority of them are never hired to such a position and ultimately change career tracks after several years. Sounds painful, but you've no choice if you want a shot at becoming a professor.
The root trouble is that most established university research professors produce many PhD students over the course of a career. By the time Professor X's retirement clears an opening for a new professor, he or she may have produced 20 PhDs. Chances are that the majority of these 20 go to sleep at night and dream of earning his slot, or one like it elsewhere.
If Professor X is often introduced as "Nobel-Prize Winner Professor X," his recommendation letters will find many of his PhD students a permanent university home. A few extremely deserving PhDs will amass such fantastic credentials that they will win tenure-track positions based on merit alone. Most applicants hired as professors will have some combination of a famous (in the research field) advisor and fabulously productive resumes.
That PhD holder who has dreamed for years of becoming a tenured faculty member faces a simple and brutal numbers game. I'll discuss my field as an example. In 2008, 1,499 people earned a PhD in physics. That same year, only 342 individuals were hired for physics faculty positions in the US. Coarsely, between four and five PhDs are produced for every tenure track hire.
We can look deeper into those basic numbers. About 60% of those hirings were for the prestigious research-focused university positions that most post-docs desire. Further, 30% of the positions were filled by someone without a PhD granted in this country. Thus there were roughly 10 US-granted physics PhDs for a single research-focused university tenure-track US faculty hire in the field. (The upside here is that if you want to teach as much as research, your chances of receiving a professorship improve substantially.)
The reason that PhDs will accept these post-doc positions is simple. The struggle for tenure-track positions is so fierce that credentials well beyond a PhD are now required to be competitive. Holding two or three consecutive post-docs is now common. Most PhD graduates are ~31 at graduation and can expect to post-doc for 3-7 years while trying for a faculty spot.
This means that your family plans are likely on hold. Or, you're willing to try to raise a family while working 50-60 hours a week, moving across the country every 24 months and making a salary of as little as $26,000. (This is low, as ~35-40K is a more standard figure in many fields). You'd do about as well working in the service industry, despite holding a hard science PhD. Of course, your spouse has to pack up and find a new job biennially too, unless you want to live 2,000 miles apart and only have dinner over Skype for two years (depressingly common).
This is purely a situation of supply-and-demand. Demand for tenure-track faculty jobs vastly outstrips the number of openings. And yet, thousands of new PhDs still aspire to compete for those precious spots. If you enjoy research more than anything else, a post-doc is for you. If you'd rather be broke and alone than not be a university professor, a post-doc is definitely for you. Prepare to work and sacrifice through several years of tough living for your shot at that dream.