AThe "Thank you" messages would have the same impact on regular patrons of a restaurant as they would on occasional patrons of the same restaurant.
BRegularly seeing "Thank you" written on their bills would not lead restaurant patrons to revert to their earlier tipping habits.
CThe written "Thank you" reminds restaurant patrons that tips constitute a significant part of the income of many food servers.
DThe rate at which people tip food servers in Canada does not vary with how expensive a restaurant is.
EVirtually all patrons of the Canadian restaurants in the study who were given a bill with "Thank you" written on it left a larger tip than they otherwise would have.