I had a professor assign his own text once (somewhere around 1996?). It was pretty expensive. At the start of the semester, he gave a $2 refund to everyone who

I had a professor assign his own text once (somewhere around 1996?). It was pretty expensive. At the start of the semester, he gave a $2 refund to everyone who had purchased a brand-new copy, since that was his share of the price we paid. I think there were about 60 students taking the class that year, so that comes out to $120. Are you really suggesting that $120/year creates some vast moral hazard for college faculty? Or even ten times that? (The "new edition shuffles problem numbers" thing is irritating to me as a professor, too, by the way. It's not clear to me that even most textbook authors are fond of the continual release of new editions, but it seems to be a big part of the publishers' business model these days.)