Koert van Ittersum

Bottoms Up! The Influence of Elongation on Pouring and Consumption Volume

Although the effects of shapes on area perceptions have been widely investigated, we replicate, extend, and generalize one of the few studies to relate the effects of shapes to consumption volumes (Raghubir and Krishna 1999). While Raghubir and Krishna demonstrate the effect of the elongation of prepoured drinks on consumption volume, we have people pour their own drinks in a series of controlled field experiments. Two experiments in cafeterias show that both children and adults pour and consume more juice when given a short, wide glass compared to those given a tall, slender glass, but they perceive the opposite to be true. We conclude that the elongation of glasses negatively influences consumption volume in a single-serving context. A third potentially policy-relevant field experiment conducted with Philadelphia bartenders and liquor shows that the effect of elongation is moderated but not eliminated with pouring experience. Copyright 2003 by the University of Chicago.

Plate Size and Color Suggestibility: The Delboeuf Illusion's Bias on Serving and Eating Behavior

Despite the challenged contention that consumers serve more onto larger dinnerware, it remains unclear what would cause this and who might be most at risk. The results of five studies suggest that the neglected Delboeuf illusion may explain how the size of dinnerware creates two opposing biases that lead people to overserve on larger plates and bowls and underserve on smaller ones. A countercyclical sinus-shaped relationship is shown to exist between these serving biases and the relative gap between the edge of the food and the edge of the dinnerware. Although these serving biases are difficult to eliminate with attention and education, changing the color of one’s dinnerware or tablecloth may help attenuate them. By showing that the Delboeuf illusion offers a mechanistic explanation for how dinnerware size can bias serving and intake, we open new theoretical opportunities for linking illusions to eating behavior and suggest how simple changes in design can improve consumer welfare.

Shape of glass and amount of alcohol poured: comparative study of effect of practice and concentration.

Abstract Objective To determine whether people pour different amounts into short, wide glasses than into tall, slender ones. Design College students practised pouring alcohol into a standard glass before pouring into larger glasses; bartenders poured alcohol for four mixed drinks either with no instructions or after being told to take their time. Setting University town and large city, United States. Participants 198 college students and 86 bartenders. Main outcome measures Volume of alcohol poured into short, wide and tall, slenderglasses. Results Aiming to pour a “shot” of alcohol (1.5 ounces, 44.3 ml), both students and bartenders poured more into short, wide glasses than into tall slender glasses (46.1 ml v 44.7 ml and 54.6 ml v 46.4 ml, respectively). Practice reduced the tendency to overpour, but not for short, wide glasses. Despite an average of six years of experience, bartenders poured 20.5% more into short, wide glasses than tall, slender ones; paying careful attention reduced but did not eliminate the effect. Conclusions To avoid overpouring, use tall, narrow glasses or ones on which the alcohol level is premarked. To avoid underestimating the amount of alcohol consumed, studies using self reports of standard drinks should ask about the shape of the glass.

Remanufacturing, Third-Party Competition, and Consumers' Perceived Value of New Products

In this paper, we investigate whether and how the presence of remanufactured products and the identity of the remanufacturer influence the perceived value of new products through a series of behavioral experiments. Our results demonstrate that the presence of products remanufactured and sold by the original equipment manufacturer OEM can reduce the perceived value of new products by up to 8%. However, the presence of third-party-remanufactured products can increase the perceived value of new products by up to 7%. These results suggest that deterring third-party competition via preemptive remanufacturing may reduce profits, whereas the presence of third-party competition may actually be beneficial for an OEM. This paper was accepted by Serguei Netessine, operations management.

Portion size me: Plate-size induced consumption norms and win-win solutions for reducing food intake and waste

Research on the self-serving of food has empirically ignored the role that visual consumption norms play in determining how much food we serve on different sized dinnerware. We contend that dinnerware provides a visual anchor of an appropriate fill-level, which in turn, serves as a consumption norm (Study 1). The trouble with these dinnerware-suggested consumption norms is that they vary directly with dinnerware size--Study 2 shows Chinese buffet diners with large plates served 52% more, ate 45% more, and wasted 135% more food than those with smaller plates. Moreover, education does not appear effective in reducing such biases. Even a 60-min, interactive, multimedia warning on the dangers of using large plates had seemingly no impact on 209 health conference attendees, who subsequently served nearly twice as much food when given a large buffet plate 2 hr later (Study 3). These findings suggest that people may have a visual plate-fill level--perhaps 70% full--that they anchor on when determining the appropriate consumption norm and serving themselves. Study 4 suggests that the Delboeuf illusion offers an explanation why people do not fully adjust away from this fill-level anchor and continue to be biased across a large range of dishware sizes. These findings have surprisingly wide-ranging win-win implications for the welfare of consumers as well as for food service managers, restaurateurs, packaged goods managers, and public policy officials.

News Media Channels: Complements or Substitutes? Evidence from Mobile Phone Usage

The media industry has undergone a fundamental shift over the past decade as new online distribution channels have proliferated in an unprecedented manner. Although mobile devices have experienced rapid adoption among consumers, their effect on consumer behavior and their subsequent implications for publishers and advertisers have yet to be understood. The authors examine consumers’ news consumption behavior on mobile news websites in response to the introduction of a mobile news app. Pseudo-panel analysis based on repeated cross-sectional data suggests that the introduction of a mobile app by a major national media company leads to a significant increase in demand at the corresponding mobile news website. In addition, the authors report that this effect is greater for consumers with (1) greater appreciation for concentrated news content, (2) stronger propensity for a particular political viewpoint, and (3) fewer time constraints. The results are consistent with the interpretation that the adoption of a providers news app stimulates corresponding mobile news website visits. The authors discuss the implications of these findings for advertisers, media publishers, and policy makers.

Fast Food Restaurant Lighting and Music Can Reduce Calorie Intake and Increase Satisfaction

Recent research shows that environmental cues such as lighting and music strongly bias the eating behavior of diners in laboratory situations. This study examines whether changing the atmosphere of a fast food restaurant would change how much patrons ate. The results indicated that softening the lighting and music led people to eat less, to rate the food as more enjoyable, and to spend just as much. In contrast to hypothesized U-shaped curves (people who spend longer eat more), this suggests a more relaxed environment increases satisfaction and decreases consumption.

Cumulative Timed Intent: A New Predictive Tool for Technology Adoption

Despite multiple calls for the integration of time into behavioral intent measurement, surprisingly little academic research has examined timed intent measures directly. In two empirical studies, the authors estimate individual-level cumulative adoption likelihood curves—curves calibrated on self-reported adoption likelihoods for cumulative time intervals across a fixed horizon—of 478 managerial decision makers, self-predicting whether and when they will adopt a relevant technology. A hierarchical Bayes formulation allows for a heterogeneous account of the individual-level adoption likelihood curves as a function of time and common antecedents of technology adoption. A third study generalizes these results among 354 consumer decision makers and, using behavioral data collected during a two-year longitudinal study involving a subsample of 143 consumer decision makers, provides empirical evidence for the accuracy of cumulative adoption likelihood curves for predicting whether and when a technology is adopted. Cumulative adoption likelihood curves outperform two single-intent measures as well as two widely validated intent models in predicting individual-level adoption for a fixed period of two years. The results hold great promise for further research on using and optimizing cumulative timed intent measures across a variety of application domains.

Larger Bowl Size Increases the Amount of Cereal Children Request, Consume, and Waste

OBJECTIVE To examine whether larger bowls bias children toward requesting more food from the adults who serve them. STUDY DESIGN Study 1 was a between-subject design involving 69 preschool-age children who were randomized to receive either a small (8 oz) or large (16 oz) cereal bowl and were asked to tell researchers how much cereal they wanted for a morning snack. Study 2 was a within-subject design involving 18 school-age children at a summer camp who were given a small (8 oz) cereal bowl on one day and a large (16 oz) cereal bowl on another day and asked by a cafeteria server how much cereal and milk they wanted for breakfast. Hidden scales measured how much cereal and milk were served, consumed, and wasted. Body mass index was calculated at the end of the study. RESULTS In study 1, the young children requested almost twice as much cereal to eat when presented with the larger bowl compared with the smaller bowl. In study 2, the older children consumed 52% more and wasted 26% more when served in the larger bowl. CONCLUSION A step toward potentially reducing overeating and waste would be for parents and adult caregivers to use smaller bowls for serving food to children.

Smart Shopping Carts: How Real-Time Feedback Influences Spending

Although interest in smart shopping carts is increasing, both retailers and consumer groups have concerns about how real-time spending feedback will influence shopping behavior. Building on budgeting and spending theories, the authors conduct three lab and grocery store experiments that robustly show that real-time spending feedback has a diverging impact on spending depending on whether a person is budget constrained (“budget” shoppers) or not (“nonbudget” shoppers). Real-time spending feedback stimulates budget shoppers to spend more (by buying more national brands). In contrast, this feedback leads nonbudget shoppers to spend less (by replacing national brands with store brands). Furthermore, smart shopping carts increase repatronage intentions for budget shoppers while keeping them stable for nonbudget shoppers. These findings underscore fundamental unexplored differences between budget and nonbudget shoppers. Moreover, they have key implications for both brick-and-mortar and online retailers as well as app developers.