Here is the abstract to the paper:
Are price and consumption independent in fixed-price service contexts? A field experiment at an all-you-can-eat pizza restaurant shows that a 50% discount on the price of the meal led customers to consume 27.9% less pizza (2.95 vs. 4.09 pieces). This difference is significant and of similar size when controlling for age, height, gender and the day of participation. Additional analysis suggests that individual ratings of taste may be inversely related to consumption within treatment. Thus those who like it more, may consume less. One interpretation of our result is that, 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.
The numbers I highlighted in bold above are put on a bar graph below to illustrate the finding.
Do we eat to satisfy our hunger (a fixed point) or to justify how much we paid for the food (a variable amount)?
If I were honest about it, I would say this relationship holds for me. I believe I eat more at Golden Corral, on average, then I do at a CiCi's Pizza. While price may not be at the forefront when I am consuming but it plays a part in how much I decide to consume, independent of how full I feel.
Don't judge me. :)