Is Your Reusable Grocery Bag Making You Indulge in Junk Food?
Let's say you're at the grocery store. You remembered your reusable bag, and as you browse the aisles, filling up your bag with brown rice, organic kale, and almond milk, you pass the junk food section, take a gander at its offerings, and slip a Ben & Jerry's into your bag. Why not, you think, it's a treat for doing good for the environment.
Turns out, you're not alone in this personal-reward-for-pseudo-hard-work response that psychologists call "licensing." That is, if you behave well in one situation, you give yourself license to misbehave in another, unrelated situation. You remember to bring a bag, you get a cookie. Literally.
And this is what Uma Karmarkar, assistant professor of marketing at Harvard Business School, and her research partner, Bryan Bollinger of Duke's Fuqua School of Business, discovered in their quantitative analysis.
The researchers pored over thousands of grocery store receipts in California, and were able to discern which shoppers had reusable bags based on the small discounts that were given to people who provided their own bags.
The data we worked with was based on loyalty cards, so we didn't just compare individual transactions. We could compare the purchases of the same people when they brought bags versus when they didn't. And we could eliminate shopping trips that didn't look like your canonical weekly trip to the grocery store. So we got rid of outlier transactions, like ones in which it was clearly a small business doing the shopping or someone picked up only two items.
Compared to shoppers who did not have reusable bags, Karmarkar and Bollinger found that the "greener" group tended to indulge in high-calorie, fat-laden junk food more often:
It was clear that shoppers who brought their own bags were more likely to replace nonorganic versions of goods like milk with organic versions. So one green action led to another. But those same people were also more likely to buy foods like ice cream, chips, candy bars, and cookies. They weren't replacing other items with junk food, as they did with organic food. They were just adding it to their carts.
Interestingly, the self-congratulatory indulgence seemed to vanish with people who had kids. The shoppers with baby items on their receipts were less likely to cave in to junk food impulses — perhaps because they were trying to set a healthy example for their kids.
Overall, the behavior seems to be subconscious, as most of us probably aren't thinking that because we're toting around a reusable bag, we deserve that doughnut. Or maybe we do. Hey, life is short.