How marketers can predict consumers’ perceptions of package and portion size

After decades of supersizing, many marketers, including consumer giants such as Coca-Cola and Kellogg, are now experimenting with smaller package sizes to accommodate soaring raw material costs, attract health-conscious consumers, and enhance consumer enjoyment.

However, product downsizing can be a risky strategy: consumers find it deceitful and associate smaller sizes with lower value for money. As a result, companies rarely announce changes in product size so as to avoid a negative consumer response.

This makes it important for marketers to be able to predict how consumers will perceive changes in package size, and to choose package dimensions that will achieve the desired size impressions. At the same time, consumers and policy makers need to understand how different changes in the size and shape of packages can influence size impressions.

However, developing packaging prototypes is an expensive business, so it is essential that marketers have a simple model to predict how consumers will respond to changes in size and shape.

Assistant Professor of Marketing at ERIM, <link people nailya-ordabayeva>Nailya Ordabayeva, and fellow researcher Prof. Pierre Chandon, have addressed this issue by developing the AddChange heuristic model of size impression. Their findings are published in the American Marketing Association’s Journal of Marketing.

This AddChange model does not require any data to accurately predict consumers’ perceptions of product downsizing and supersizing when one, two, or all three dimensions change proportionately, or when the products become elongated. Rather, it works on the premise that people add (rather than multiply) the percentage changes in the height, width, and length of objects to compute their volume.

Decision makers using the heuristic formula will be able to ascertain how people will perceive regular package size changes without designing prototypes and conducting costly empirical tests.

The findings have important implications for both marketers and policy makers, particularly as the model can be used to determine the dimensions of packages that create accurate size perceptions or those that increase consumers’ acceptance of downsizing.

• Download Predicting and Managing Consumers' Package Size Impressions. Journal of Marketing from the American Marketing Association