Answering the “why do you want to do a PhD?” question

Question

This question is ubiquitous when applying for PhD studies, and it's one I don't understand. On the surface it's a simple question, but I found it to be frustratingly complex.

I tend to think in economic terms. My calculations indicated that PhD studies are not worth it, especially in a world of exponential growth. The details aren't that important, but briefly, I calculated that if I stay in industry and invest most of my salary into the stock market, I can expect to greatly outperform someone who spends 4+ years in a PhD program unless he or she commands a very high starting salary, which is usually not the case. This doesn't take into account the fact that 49% of PhD students are depressed and half of them don't complete.

So since the economic argument is a failure, when I wrote my PhD applications, I put in all the other reasons I had to do it, such as:

1. I felt I'm in a dead-end job where my skills aren't appreciated. A much less-trained person can do what I'm doing, and while I believe I do a better job, I do so in ways that management does not track.
2. I wanted to swap careers. To do that I needed a new set of skills, and further study would not only let me pick that up, it would let me back up my skills with a paper qualification. Since I already had a Masters degree a PhD is the next obvious thing to do.
3. I choose this field because it provides transferable skills to the careers I want to move to, and because I'm sufficiently interested in it to want to keep up to date with its most recent developments (even though I probably won't stay in it as a researcher, per the fact that the odds of finding an academic job are very low).
4. I did well in my Masters (which was in the same field), including the research component, so I believe I can also do well in a PhD.
5. I can afford it. I hadn't been in the workforce for long, but I'm extremely conservative with money and we've been in a bull market for the past several years. Of course I would rather not self-fund, but if I have to, I can.

When I showed these reasons to my professors, they responded with "you are telling them why they shouldn't admit you!" Following their advice I rewrote my statement of purpose to what I'll call half-truths, which got me admitted.

I don't understand why my original reasons to do PhD studies weren't valid. I'm happy doing what I'm doing right now, and my supervisor has said I'm progressing well. That seems to be indicating that my original reasons aren't inappropriate. I further don't understand why PhD programs care about the reasons why the student is doing a PhD. It seems much more natural to worry about whether the student is capable of doing it. Certainly the latter question was the focus of all my non-academic job interviews. Finally it seems admission committees like candidates who are passionate about the field and want to become researchers themselves. However I also see plenty of complaints by academics about academic life (e.g. the funding lottery, the nomadic lifestyle). If academics are trying to convince students that they shouldn't try to be researchers, why are they turning around and looking for people who want to be researchers? It feels like they prefer the ignorant and starry-eyed over those who're aware what they're going into.

Can someone explain?

Answer 1

If a school is acting morally, then it takes pains not to admit students who are unlikely to succeed. So we give the SAT to high school students and hope the score predicts whether they are apt to graduate college. (I know of a school which lost it's state funding because they admitted too many ill-prepared freshmen and over 50% of the freshman class dropped out that year. It appeared on the surface that the school simply let them in, took their government financial aid, and let them fail. IMO, this was fraud. Also in the state's opinion.)

So how to we decide if a person will be a successful Ph.D. student? We want someone who is enthusiastic about the subject and someone who will contribute to the on-going mission of the department. I think most of us believe that the type of student we're looking for will be internally motivated. All of your reasons are external motivations. We'd like to know that the reason you're with us is because the craving for this type of knowledge is part of YOU, not part of the circumstances you happen to find yourself in at the moment. Internal motivation is more permanent and more stable. Your external motivations can change at any moment. If you win the lottery, will you immediately drop out of the program and leave a pile of dirty test tubes for someone else to clean up?

I look at your first 3 reasons and think, "The instant this guy gets an offer he likes, he's gone. He's a mercenary."

Answer 2

Let's consider why "you are telling [professors that] they shouldn't admit you!":

1. I felt I'm in a dead-end job...

That doesn't show motivation for doing a PhD.

2. I wanted to swap careers...

You don't need a PhD to swap careers.

3. I choose this field because...

...it provides transferable skills to the careers I want to move to...

This requires more detail to be relevant.

...because I'm sufficiently interested in it to want to keep up to date with its most recent developments...

You can do that without a PhD

...(even though I probably won't stay in it as a researcher, per the fact that the odds of finding an academic job are very low).

This doesn't show motivation for doing a PhD.

4. I did well in my Masters (which was in the same field)...

Many "do well" in their Masters, PhD students do better.

...including the research component, so I believe I can also do well in a PhD.

This requires more detail to be relevant.

5. I can afford it.

This doesn't distinguish you.

Answer 3

Performing a PhD thesis can be tough at times; there are times when your experiments do not deliver the results you want, when your articles are being rejected (sometimes with unjustified criticism, or at least it appears so to you), when you are working long hours, when you are suffering from writers block, when you have to teach unmotivated students, etc etc etc.

https://www.google.com/search?q=PhD+blues

Not all of the above may happen to you, but some of it may occur at times. And in certain fields and geographies you are absolutely right about the economics; a career in industry may pay more than in academia.

So when asked the question "why do you want to do a PhD?", people are looking for your motivation. They would like to see candidates who are intrinsically motivated, who like doing research, who like to publish, who like to contribute to academic knowledge. Because these kind of people are most likely to overcome the hurdles described above.

Answer 4

A PhD is essentially an apprenticeship in research, for academia or industry. If you are not interested in a research based career, don't apply for a PhD. If you want to push forward the state of the art in your field, then a PhD ought to be excellent training, but if you just want an advantage in the job market or to stay up-to-date, then there are likely to be better approaches.