Grad students who are pursuing Ph.D. degrees are usually paid a stipend so they can afford to live very modestly. But getting that degree takes years and at the end, many of the students are frustrated in their search for a tenure-track faculty job. That’s why colleges and universities can hire adjunct faculty so inexpensively — the market is glutted with people who have the credentials.
There are also the opportunity costs of devoting so much time to the academic paper chase, such as starting a family. As writer Ben Cohen points out in this Martin Center article, our system compels most Ph.D. seekers to choose between the pursuit of the degree and a family.
The status quo works nicely for the universities, but should it really take so long and cost so much to earn a doctorate?