Economics departments eliminated methodology courses by training out all qualified instructors

Evidence

Then, by the 1990s, by construction there was no longer any call for offering courses in philosophy or history of doctrine, since there were no economists left with sufficient training (not to mention interest) in order to staff the courses. Economists would periodically be sounding off in the most illiterate registers concerning Karl Marx, Vilfredo Pareto, Hyman Minsky, Adam Smith, or even John Maynard Keynes, because they were confident no one would ever call them to task on their shallow pretenses. — Philip Mirowski, Never Let a Serious Crisis Go to Waste, 460

Categorization

• XREF: This self-reinforcing ‘no qualified staff to teach it’ dynamic parallels the institutional death spiral described in other domains like medieval Latin schooling. — connects to: Economic heterodoxy declined because graduate training filtered out non-economists — Philip Mirowski, Never Let a Serious Crisis Go to Waste, 64