I think you are mis understanding "Sunk cost fallacy". What the parent comment was saying, and something I'm quite familiar with, is that when you have investe

I think you are mis understanding "Sunk cost fallacy". What the parent comment was saying, and something I'm quite familiar with, is that when you have invested a lot of time and money in getting a Phd, and then find the job prospects slim to none, you are likely not to just give up and take a different job outside your field because you have "sunk costs" into becoming an academic. Thus, you may take a job as an adjunct in hopes of getting to be a professor someday, even if your economic position may be better to just get a job in industry somewhere.