Trigger Foods: The Influence of “Irrelevant” Alternatives in School Lunchrooms

Rational choice theory commonly assumes that the presence of unselected choices cannot impact which among the remaining choices is selected-often referred to as independence of irrelevant alternatives. We show that such seemingly irrelevant alternatives influence choice in a school lunch setting. In these lunchrooms, we provide evidence that the presence of specific side dishes - trigger foods - can strongly increase the sales of unhealthy a la carte options, even when the trigger foods are not selected. This behavioral anomaly can be exploited to lead children to healthier choices. We also offer a method that can be used to identify such foods.