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Faculty Insights

Associate Professor Evan Polman’s Nudges Research Featured in Harvard Business Review

By Wisconsin School of Business

May 1, 2024

Could you benefit from a little extra push to make a decision—whether it’s finally booking that vacation, fitting a quick walk into your lunch hour, or picking what to defrost for dinner?

Behavioral science describes such pushes as “nudges.” These small interventions are designed and tested by researchers to better understand the when, how, and why of what we do. Marketers frequently use these interventions to sway consumers toward one of several options, like signing up for a health club or selecting a cable provider.  

A new study by Evan Polman, published in the Journal of Consumer Research and featured in Harvard Business Review, looked at participant behavior and nudges across three different tests. The study found that while nudges may influence people to commit initially, that effect may wane significantly over time.  

Polman is an assistant professor in marketing and Kuechenmeister-Bascom Professor in Business at the Wisconsin School of Business.

As Polman explains in Harvard Business Review, a 2012 study by outside researchers used healthy snacks and nudges to see if it created healthier behaviors. Even though the research team positioned fruit and vegetable options in visible places, subjects took the fruit but rarely ate it. The study underscored the difference between choices made and follow-through: The nudge was effective in subjects picking up the fruit, but it didn’t change their behavior—most never consumed it.

Building with that insight in mind, Polman and co-author Sam Maglio, professor of marketing and psychology at the University of Toronto, designed a study employing three common types of nudges used across three experiments: a pre-selected “default” option; a “decoy” option to throw off the participant by making the other choices look better; and a “compromise” option that found middle ground between the other two.

In the first experiment, Polman and Maglio designed a daily trivia membership plan with several options, all equally appealing, but designating only one as the default plan which participants could opt out of (however, marketing literature shows they generally do not). Over an eight-month period, participants who initially received a nudge for the default plan—the 2012 study equivalent of the available fruit—interacted with their trivia content 42% less than those who had chosen a plan themselves without a nudge.

“Behavioral economics and nudges have revolutionized decision-making, but our research underscores a crucial insight: While nudges excel at shaping initial choices, they may falter in sustaining long-term behavior.”

—Evan Polman

A second test used a decoy nudge, advertising a “Trivia Expert for Kids” version of the trivia membership, which turned off participants enough to drive them to the “Trivia Expert” plan. Activity fell off quickly here as well within eight months. Although more people chose the nudged plan, “it increased churn,” Polman tells Harvard Business Review. “Participants used the program less when we nudged them into it.”

The third and final test nudged participants with the compromise effect using an air plants giveaway, making sure to describe the plants as nothing too complicated to maintain, nothing too special—just in the middle, average. Despite the fact that all participants received the same plant, 16% more air plants owned by participants who were nudged perished over a nine-month period compared to those who were not nudged with the compromise option.

In summary, results across all three tests suggested that while the nudged option was the most popular in the beginning, participants who chose for themselves used or consumed their option longer than those for whom it was nudged—the outcome Polman and his co-author had long wondered about and hypothesized in the paper.

“Behavioral economics and nudges have revolutionized decision-making, but our research underscores a crucial insight: While nudges excel at shaping initial choices, they may falter in sustaining long-term behavior,” says Polman. “Understanding this nuanced impact is essential for designing effective programs that drive lasting change.”

Polman joined WSB in 2013. His research examines self-other differences in decision-making, creativity, gift giving, psychological distance, and moral psychology. He was granted the Hillel Einhorn New Investigator Award from the Society for Judgment and Decision Making for his research self-other decision-making. A recipient of numerous research and teaching awards from WSB, Polman was given one of only 10 Distinguished Teaching Awards in 2019 from the University of Wisconsin–Madison. In addition to the Harvard Business Review, his research is frequently featured in national media outlets such as The Wall Street Journal and The New York Times.