Shop Till You SHOP? New Study Shows Shoppers Don't "Drop"--They Just Keep on Shopping

New Haven, Conn., December 1, 2004—As consumers flood malls and online retailers this holiday shopping season, a new study of shopping behavior by researchers at the Yale School of Management and Duke University explains why some consumers may buy more than they intend.

The study, conducted by Ravi Dhar and Uzma Khan of the Yale School of Management and Joel Huber of Duke University, demonstrates that consumers who purchase one item are more likely to continue shopping and buy more. Taking a metaphor from physics, the authors term this propensity to buy the “shopping momentum effect.”

“The idea of shopping momentum goes against a strictly rational view of consumer behavior in which the decision to purchase any product is based on its cost and benefits. Our research clearly shows that the willingness to buy an item can be enhanced merely by inducing consumers to make the first purchase,” said Dhar, a Professor of Marketing and Director of the Center for Customer Insights at the Yale School of Management.

The shopping momentum effect arises out of a shift in consumers’ thinking that occurs when they move from browsing to buying. Browsing is characterized by deliberation—consumers evaluate whether or not to purchase the item—which acts as a mental hurdle to buying. Buying involves thoughts of implementation: consumers have decided to purchase and think about carrying it out. Once an initial purchase is made, the momentum of the psychological impulse to buy drives the purchase of subsequent items, even if they are unrelated.

In the study, the authors demonstrate the shopping momentum effect by comparing consumers’ likelihood of purchasing a target item while manipulating the purchase incidence for an initial item. Among the findings: the shopping momentum effect is more likely to occur when the first item purchased is utilitarian such as an umbrella, a snow blower, or back-to-school supplies. The effect is less likely to occur if the consumer considers the first item to be a guilty pleasure.

“Guilt is an excellent psychological deterrent. If a consumer feels an item is a guilty pleasure—candy, tabloid magazines, or an expensive handbag, for example—the guilt will likely inhibit the purchase of a second item,” said Dhar.

While the study shows that consumers, with the exception of compulsive shoppers, are largely unaware that one purchase they’ve made affects another, retailers have long recognized the value of the shopping momentum effect as evidenced by tactics to induce a first purchase such as attractive prices or holiday specific items. For retailers hoping to cash in, the study suggests the most effective means of initiating a first purchase.

“The study results suggest the best driver of subsequent purchases is a highly desirable item such as a seasonal or emergency good at reasonable prices,” said Dhar.

Ravi Dhar is Professor at the Yale School of Management. Joel Huber is Professor at the Fuqua School of Business at Duke University. Uzma Khan is a doctoral candidate at the Yale School of Management.

The Yale Center for Customer Insights at the Yale School of Management is a research center devoted to studying the behavior of customers. The Center welcomes inquiries from organizations interested in research partnership and sponsorship opportunities. For more information contact Eugenia.hayes@yale.edu .