a boy eating a pizza

Source: Joe King

Psychologists at Cornell University wanted to see if people actually eat as much as possible at an “all-you-can-eat” buffet. If they do, then we should generally expect to see the same levels of consumption, regardless of how much a buffet costs. It shouldn’t matter if the buffet costs $10 or $100, you should eat the same amount – as much as you can!

So the researchers worked with a pizza buffet in Chicago and tried two different pricing conditions: one at regular price ($6 all you can eat pizza) and one at half-price ($3). 

At the regular price, buffeteers ate about four slices on average. But when the price of the buffet was slashed in half, pizza eating dropped 27%. People only ate three slices!

chart, bar chart

Data via Cornell Food Psychology

So which is it people? Is “all you can eat” three slices of pizza or four? According to the authors of the study, these findings are an example of the Flat Rate Pricing Paradox:

“Within this flat rate setting, individuals are consuming to get their money’s worth rather than consuming until their marginal hedonic utility of consumption is zero.”

So when we go to buffets, we’re not necessarily trying to eat until we can’t eat anymore. Our appetites are not blind to the price; we’re just trying to eat enough to feel like we got a good deal.

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