Should you do a PhD in science?

PhDs get a lot of negative hype these days, so much that I wonder if it is potentially underrated it as a viable career step. I am just coming out of a PhD programme in the UK, and while I didn't always enjoy my topic nor want to continue research in my field, I still think it is overall a positive experience. It is important to realize that most people starting PhDs are well aware of the low chances of becoming a professor, but luckily there are still many good career options outside academia (however I do think all the negative hype around academic careers probably means that it is also underrated relative to its true value). Some of the good aspects of (science) PhDs are:

- Lots of flexibility. You are basically guaranteed an income for ~4-5 years that you cannot lose no matter how poorly you do. While your supervisor certainly has some influence over what you do during this time, you are surprisingly free to work on what you want.
- High potential for growth. You get to experience just how difficult it is to become a world expert in something, albeit very niche, because most often you are the first to attempt your line of research. Learning about what has been done before in a field, how to find a viable approach, and how to overcome unexpected setbacks are very transferable skills.
- This is a bit more speculative, but I'd reckon that you have higher chances of landing an intellectually stimulating career with a PhD compared to a Master's degree, at least in fields where credentials matter. I'd also reckon that as a PhD plus a few years experience you are likely to get promoted to leadership positions faster.
- Many fields EAs care about (nuclear security, biosafety, AI etc.) are very science-heavy fields where having a PhD is useful. For example, with a Physics PhD it would be relatively easy to get a job in either of these, since your skillset is sufficiently adaptable to most analytic fields. 

It is hard for me to think of much advice that has gone worse for rationalists/EAs on average than 'Get a PHD'.  I know dozens of people in the community who spent at least some time in a PHD program. There is a huge amount of people expressing strong regret. A small number of people think their PHD went ok. Very few people think their PHD was a great and effective idea. Notably, I am only counting people who have already left grad school and had some time to reflect. 

The track record is incredibly bad in the community. The opportunity cost is extremely high. I very strongly urge people to reconsider. 

Another angle is that it is just a very unhealthy environment on average. Here is Ben Kuhn explaining the data:

First I looked for a bigger survey of graduate student depression and anxiety rates. It wasn’t too hard to find one, and the numbers were almost the same: 41% of graduate students had “moderate to severe” anxiety compared to 6% of the general population; 39% had moderate to severe depression compared to 6% of the general public.

For the very specific point made at the beginning, I don't think most scientific fields are pyramid schemes, unless by pyramid scheme you mean anything where there's a lot more people at the bottom than the top and the top is more desirable than the bottom (Like I don't think large companies like Google are pyramid schemes, unless you really stretch the term).  

Words are made by man, but I guess (removing normative judgments) my understanding of a pyramid scheme is a situation where a) many people at the bottom want to be at the top, b)  the success of the people at the top is a direct result of contributions from people at the bottom, and c) most of the incentive for work for people at the bottom is the excess returns at the top.

In that regard, legal pyramid schemes include poker, some arts, and some humanities. Also (more archetypally) multilevel marketing etc. I can also sort of see a case for professional e-sports/gaming, though I think the case is much weaker than for poker. 

In contrast, undergrad education in STEM (eg chemistry or CS) and some of the social sciences is both directly useful and relevant signaling that prepares people for non-academic jobs. Depending on the subfield, this is often true for PhDs as well, though the case for postdocs might be lower.

I suspect 1/3 is a significant overestimate since US universities attract people who did their PhDs all across the world.

Mental health effects are the reason I stopped considering doing a PhD. This might be specific to economics, but here’s one study that surveyed Econ PhD students:

“We find that 18% of graduate students experience moderate or severe symptoms of depression and anxiety — more than three times the population average — and 11% report suicidal ideation in a two-week period. The average PhD student reports greater feelings of loneliness than does the average retired American. Only 26% of Economics students report feeling that their work is useful always or most of the time, compared with 70% of Economics faculty and 63% of the working age population.”

https://scholar.harvard.edu/bolotnyy/publications/graduate-student-mental-health-lessons-american-economics-departments

Then again, a one-in-three chance of tenure after graduation isn’t so bad! (I did an estimate of my own using sources I’ve long since forgotten and came to a similar conclusion for economics — my guess was that 33% to 50% of graduates at top 30 schools get tenure track roles, and most of those end up getting tenure.)

15% does not sounds too bad.

15% seems to me like very bad odds for a multi-year training program, especially given it doesn't count people who start a PhD program and then drop out.

See also http://www.shouldyouphd.com/