I was thinking that, if I were in an economics class and had to write a paper, I'd want to do it on this topic: what would different historical economists have to say about how much you should tip attractive waiters and waitresses?
I was originally going to mention Adam Smith here, but I'm not going to show my ignorance by losing the "match the economist to the theory" game, so let's just call my theoretical economist "Madam Sith." I like the ring to that. Madam Sith believes that people in a capitalistic society will act selfishly, but everyone acting largely selfishly will actually yield the best possible outcome for society as a whole. Would she, then, tip well so as to encourage that hot waiter to stay a waiter forever, or would she tip lightly to save as much income for herself? What if the waiter was just working a temporary job to pay for school, and was eventually looking to get into the same field of work as Madam Sith? Should Madam Sith tip very poorly to encourage him to study hard and get out of waiting tables as soon as possible?
These are the questions that need answers... these are the questions that should be answered by a sophomore economics student in a class paper.