URBANA, Ill., USA – Self-checkout registers have become ubiquitous in grocery stores as they provide convenience and efficiency for customers. They also offer more privacy with no human directly monitoring your purchases. A new study from the University of Illinois Urbana-Champaign looks at whether shoppers prefer self-checkout when buying potentially stigmatized items, including condoms, pregnancy tests, period products, hemorrhoid cream, and diarrhea relief.

“We were really interested in whether automation technologies such as self-checkout, which eliminate human interaction, change what people buy. When you're at a cashier register, the cashier sees everything you purchase. When you're at self-checkout, you can control what others see, so you might be more likely to buy embarrassing items,” said Becca Taylor, assistant professor in the Department of Agricultural and Consumer Economics (ACE), part of the College of Agricultural, Consumer and Environmental Sciences at Illinois.

Taylor and her colleagues analyzed purchase scanner data from a large grocery store chain with locations in Washington, D.C., Maryland, and Virginia between 2008 and 2011.

“This period comprised the initial rollout of self-checkout, which helps us better understand the impact. This was the first time that self-checkout was available to shoppers, and we could see how they responded to it,” Taylor said.

The study focused on two main questions: Whether shoppers under-purchased embarrassing items before self-checkout was available, and whether they were more likely to prefer self-checkout to cashier registers for those purchases.

First, the researchers compared purchases of stigmatized products before and after a store had introduced self-checkout, using a random sample of transactions from 30 stores.

“We find that sales of condoms, bowel treatments, and yeast infection products increased when self-checkout was available. But for other items, such as period products, we did not see an increase in sales. Potentially, this is the difference between products you need no matter what, and products you could go without or delay purchase,” Taylor said.

Next, the researchers compared purchases from cashier registers versus self-checkout, based on data that included every transaction during the afternoon shopping hours at 51 stores over three years. They found that overall, 19% of items were purchased at self-checkout; however, the number was much higher for stigmatized items – especially condoms and pregnancy tests, where 42% and 43% of sales, respectively, switched to self-checkout.

This effect held up when the researchers controlled for other factors. Even if people bought a large number of items, or if they bought fresh fruit or vegetables — which need to be coded and weighed — they were much more likely to choose self-checkout if the purchase included embarrassing items.

These findings show that people prefer the privacy of self-checkout for certain products, even at the cost of longer checkout time, Taylor noted.

“It may seem like time goes quicker at self-checkout because you are doing all the work yourself. But cashiers can scan much faster, and transaction time is on average 100 seconds shorter. There is a tradeoff between the additional effort at self-checkout versus the privacy gained.”

Recently, some stores have begun to roll back self-checkout, citing customer desire to interact with cashiers. While this study showed that people prefer self-checkout for some purchases, there are good reasons to offer both options, Taylor stated.

“We found there are some products, particularly fresh produce, floral items, and bulky dog food, that people would rather buy at a cashier register where they can have help,” she said. “This suggests that fully switching to self-checkout would not be welfare-enhancing for consumers. People benefit from being able to decide which type of register to choose.”

The paper, “Does Automation Reduce Stigma? The Effect of Self-checkout Register Adoption on Purchasing Decisions” is published in the Journal of Economic Behavior and Organization [DOI: 10.1016j.jebo.2025.107126]. Authors include Rebecca Cardinali, Lester Lusher, Rebecca Taylor, and Sofia Villas-Boas.