Checking Out Temptation: A Natural Experiment with Purchases at the Grocery Register

A long literature in psychology, as well as a more recent theory literature in economics, suggests that prolonged exposure to a tempting stimulus can eventually lead people to "succumb" to that temptation. Here we develop a simple model of decision under temptation, and test its predictions using data from a natural experiment. We take advantage of naturally occurring, exogenous variation in the amount of time individual consumers spend waiting in grocery store checkout lines. We collect over 2,800 observations from three grocery stores. We obtain robust evidence that time spent in line economically and statistically significantly increases the probability that one purchases a tempting item. For example, people who wait in line 25 percent longer than average are between 12 and 25 percent more likely to purchase a tempting item. Moreover, for any fixed time in line, we find that the presence of a child significantly increases the likelihood of a purchase. These results are consistent with models that connect purchasing decisions to temptation, and also suggest that children yield to temptation more rapidly than adults. Our results offer novel quantitative and empirical content to the rapidly expanding economics literature on decisions under temptation.


First version: August 2004

This version: August 2007

Download the manuscript.