Because they will, out of the habit, mentally compare those prices to the prices they are used to see printed in the menu. Basically double-counting all the tax

Because they will, out of the habit, mentally compare those prices to the prices they are used to see printed in the menu. Basically double-counting all the taxes and fees. They do not say it will create higher prices, it will create AN IMPRESSION of everything getting more expensive. It's all about perception, that will cause people to be more frugal.