Case Detail

Encouraging Environmentally Friendly Shopping using Prompts, Commitment and Norms

 Case Contact Information


Dr. Doug McKenzie-Mohr




McKenzie-Mohr Associates



Customers at a Zehr's supermarket in Kitchener, Ontario were encouraged to purchase environmentally friendly products. 168 products were identified that either had least-waste packaging, were concentrated and/or were safer cleaner choices. Utilizing electronic inventories, the sales of these 168 items were monitored for two weeks at this and at another Zehr''s store that had a similar clientele and carried the same products. Following this baseline period, a two week promotion was begun at one store while the other store served as a control. During the two-week promotion environmentally friendly items were identified in the store via brightly colored shelf-talkers that were placed directly in front of the environmentally friendly items (see the chapter on prompts in the online guide at this site for further information on the use of prompts). In addition, three posters drew attention to the shelf-talkers as did several thousand fliers that were handed out at the store entrance. In addition, the impact of written commitments, modeling and norms were tested. To test the impact of these behavior change tools upon purchases, for one day shoppers were randomly assigned to one of three conditions as they entered the store. Some shoppers were asked to make a written commitment to shop for environmentally friendly products, others were asked to watch a video (1-2 minutes) that modeled purchasing the products and suggested that it was the "right think to do", while others were asked to sign the commitment and watch the video.


Analysis of electronic inventories indicated that the prompts did not increase the purchase of targeted items. That is, items that were identified with shelf-talkers (prompts) as having least-waste packaging, being concentrated and/or as safer cleaner choices were no more likely to be purchased during the promotion than they were during the baseline period. Further, those shoppers who were specifically asked to make a commitment to consider purchasing these products, watch a video that modeled the purchase of these products, or both, were not more likely to purchase these items than were another group of shoppers of which these requests were not made. While this project did not produce the expected results, these findings should not be interpreted as evidence that these approaches will not work. Future initiatives will need to address several problems that we experienced with this project. First, we were able to only place shelf-talkers in front of a limited number of products (168). An average supermarket has over 17,000 items! In other words, so few items were targeted that shoppers had little opportunity to purchase environmentally friendly products even if they were inclined to do so. Further, the shelf talkers that we used were fairly long (about 6 inches) which led to a large number being knocked of the shelf by carts. At one point over 1/3 of the shelf talkers had been knocked down. Finally, the success of similar initiatives (such as the buy-recycled initiative in Western Washington state -- see the chapter on prompts in the online guide) suggests that if these problems are overcome this strategy can be very successful in influencing purchases. More details on this case can be found at:
Note: This project was the honors thesis of Nancy Gallant and was supervised by Doug McKenzie-Mohr. Vivian De Giovanni from the City of Waterloo was immensely helpful in carrying out this project.

Tools: Commitment, Norms, Prompts

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