One of my favorite parts of Bryan Caplan's book, The Myth of the Rational Voter, is where he talks about the importance of being able to get rich by solving problems. I remembered his statement only approximately but over the three years since I've read his book, I've used the statement in my lectures and, as often happens, honed it a little more each time.
I used it when summing up the importance of incentives in my last class last week. So Bryan gets the credit for the idea. Here's my version:
Non-economists often get upset when they learn that someone has gotten rich by solving a problem. Economists, by contrast, worry when they think no one can get rich by solving a problem.