Consider two Italian restaurants located in identical towns 200 miles apart. The restaurants are identical in every respect but their tipping policies. At one, there is a flat $15 service charge, but no other tips are accepted. At the other, a 15 percent tip is added to the bill. The average food bill at the first restaurant, exclusive of the service charge, is $100. How, if at all, do you expect the amount of food eaten in the two restaurants to differ?