So here, succinctly, is my advice:
Enroll in a Ph.D. program only if you think you'll enjoy graduate school. Don't enroll just because you think a Ph.D. will help you in your future career. In other words, don't go to graduate school as a means to an end.Note: my advice is meant for US students seeking a Ph.D. in the sciences. It probably applies more broadly.
Yale's computer science building, Arthur K. Watson Hall, where I spent a lot of time in grad school. Image from here.
My advice may seem obvious, but it's not. For instance, this would be bad advice for students considering an M.D. -- almost nobody enjoys medical school, but I think few graduates regret having gone.
But there are three main reasons why this is the right advice for grad school.
- In Ph.D. programs, unlike in many of the professional schools, you're supposed to be doing pretty much what your professors do -- research. Sure you have to take some classes and get paid less, but chances are if you don't enjoy grad school, you won't enjoy a research career either. (Going to grad school to pursue a finance career or something unrelated later is doing it the hard way.)
- Jobs in research, and especially in academia, are scarce, and going to grad school just because you might like a research job later is a very unsafe bet. So, going to grad school only makes sense if you'd enjoy the research career, and also if you'd enjoy the experience anyway if a research career doesn't work out. Four to six years of your life is a long time to be miserable.
- Grad school, unlike professional school, has no end-date. You finish when you've done enough. And it's hard to do enough if you're not enjoying the work. Forcing yourself to sit through anatomy is one thing; forcing yourself to be creative is quite another.
That being said, I don't mean to be negative. I'm very happy I went to grad school -- I had a great time there and am lucky to keep on getting to do research. So, if you want to get a Ph.D., go for it. Just remember to enjoy the journey.