My understanding is that this problem is in part due to the huge boom in higher education after WWII. Departments got into a growth mode where they produced mo

My understanding is that this problem is in part due to the huge boom in higher education after WWII. Departments got into a growth mode where they produced more ph.d.'s than were needed to replace the present generation of college professors. When the grow came to an end in the 1960's, they should have cut way back on graduate students, but they didn't, and so we now have a great surplus of would-be professors as compared to the number of available slots.