Why Consumers Underestimate Size Changes and How to Help Them
02 / 2012 - 02 / 2015
Recent decades have witnessed a dramatic supersizing trend in product packages and food portions in Western economies. Since larger packs lead to greater consumption intake, the supersizing trend is often identified as one of the prime drivers of overconsumption and obesity. Large packs increase consumption partly because people underestimate changes in size and therefore do not realize just how large supersized packs are. This underestimation bias boosts consumers? serving and consumption quantity, quantity discount expectations, and preferences for large sizes. It is therefore critical to understand the sources of the underestimation bias in order to formulate public policies and marketing strategies for improving the accuracy of consumers? size perceptions and healthfulness of their decisions. This research will use experimental methods to achieve these goals. Two potential mechanisms can explain the underestimation bias: biased information attention (whereby people focus on the package?s salient dimension when estimating its total volume) and biased information integration (whereby people use an erroneous model such as adding individual package dimensions, instead of multiplying them, to estimate volume). In a series of experiments, this research will investigate: (1) the role of the two mechanisms in explaining the underestimation bias, (2) the strategies that improve the accuracy of consumers? size perceptions; and (3) whether the underestimation bias, its mechanisms and remedies guide consumers? perceptions of package and portion downsizing and changes in products? sensory attributes (concentration, taste, scent, and color), which are increasingly common due to increasing production costs, recessionary economy, and public pressure to improve product healthfulness. The findings about the sources and remedies of the underestimation bias and how they generalize to perceptions of size decreases and changes in products? sensory attributes will suggest policies to help consumers better monitor their consumption quantity and quality, which in effect will inform policies for fighting overconsumption and obesity.