What’s the best way to convince shoppers to swap disposable grocery bags for a reusable alternative?
Some stores and localities impose a small tax on disposable bags, while others go the route of positive reinforcement by giving people a small bonus for using reusable bags.
Until now, not much information was available about which method works best, but a new Princeton dissertation sheds some light on the issue.
In her three-part, 141-page dissertation, fresh Ph.D. graduate Tatiana Homonoff examined shopper behaviors to bring hard numbers to the reusable bag dilemma.
After observing more than 16,000 shoppers at 16 grocery stores in Washington, D.C.; neighboring Montgomery County, Md.; and northern Virginia and examining data from store scanners, Homonoff found that a 5-cent tax on disposable bags substantially decreased disposable bag use, while a 5-cent bonus for using a reusable bag did not.
Before the tax, several Washington, D.C., stores offered a 5-cent bonus to shoppers who brought their own bags. In stores that didn’t offer a “bag bonus,” 84 percent of shoppers took at least one disposable bag per shopping trip. In stores that offered the bonus, 82 percent took a disposable bag.
As you may imagine, that 2 percent decrease is less than desirable for grocers and environmentally minded legislators. It’s worth noting, though, that in Montgomery County the bag bonus decreased disposable bag use from 82 percent to only 40 percent of shoppers — indicating that the incentive-based model isn’t completely without warrant and may yield significant benefits in some cases, depending on the demographics.