Two issues: 1. That would mean redefining enrollment. What if a PhD student takes a class that involves instruction time during their research period - as I di

Two issues: 1. That would mean redefining enrollment. What if a PhD student takes a class that involves instruction time during their research period - as I did, and as some of my students will likely do? 2. The money used to pay the instructors for PhD-level classes, of which there are some, has to come from somewhere. And for many universities, there is $0 that is "irrelevant".