Do Promotions Make Consumers More Wasteful? The Effect of Price Promotion on Consumer Food Waste Behavior

Consumer food waste is a major global challenge to sustainable development, generating massive carbon and water footprints, exacerbating food insecurity, and undermining the United Nations Sustainable Development Goals. While extensive research has documented individual and contextual drivers of consumer food waste, critical gaps remain in understanding how core marketing tools shape wasteful behavior, particularly the unintended post-purchase consequences of ubiquitous price promotions. Addressing this gap, we unpack the psychological mechanism underlying the classic social dilemma of promotions: short-term individual economic savings from discounts conflict with long-term collective ecological welfare. Across four rigorous studies, including a real-world field experiment in a university canteen, we establish a causal effect of price promotions on increased consumer food waste behavior. We further demonstrate that this effect is mediated by enhanced perceived resources: price promotions generate subjective feelings of windfall gains and resource abundance, which in turn increase consumers' willingness to discard edible food. We identify two practical actionable boundary conditions that attenuate this pro-waste effect: the impact of price promotions on food waste is eliminated when consumers focus on money spent (rather than money saved) from the transaction, and when they perceive their spending as exceeding their psychological budget. Our findings advance the literature on price promotions and sustainable consumption by documenting a previously unrecognized hidden cost of promotional marketing, unpacking the micro-psychological foundations of the social dilemma in food waste decisions, and providing evidence-based, actionable implications for policymakers, food retailers, and food service operators to curb promotion-induced food waste.