A finance professor at HEC Paris, Stefano Lovo received the Faculty Impact Award alongside Yurii Handzjuk (D.25) during the 48th HEC Foundation Awards ceremony on March 10. Their prize-winning study is based on an original experiment conducted at the HEC cafeteria, demonstrating the role of financial incentives in encouraging environmentally responsible behavior.

Turning the HEC Paris cafeteria into a laboratory for studying the levers of more sustainable food services? He did it! Between August 2021 and mid-June 2023, Stefano Lovo analyzed the choices of 4,000 users of the school’s cafeteria to determine the best strategy for reducing the carbon footprint of their meals.
“Three levers can influence diners’ choices,” Stefano explains: “a bonus-malus pricing system that makes low-carbon meat dishes cheaper than high-carbon ones, the outright removal of high-carbon dishes, or the display of the carbon footprint of each dish. According to an online survey designed by a student in 2020, simply informing consumers was enough to get them to choose low-carbon options. I wanted to test this in real conditions.”

“I’m a theorist first and foremost,” says Stefano, an expert in information economics and game theory, who turned his attention to sustainable finance after Covid and took over as head of the HEC Center for Impact Finance Research in 2024. “The cafeteria study was empirical. That’s why I conducted it with Yurii Handzjuk (D.25): I needed an econometrics expert by my side.”
The experiment involved many stakeholders across campus. Approval had to be secured from the school’s leadership and the food service manager. Data had to be collected and anonymized with help from the IT department. Students had to be involved, and staff unions reassured that the increase in meat dish prices would not penalize employees: “They were reassured once we showed them that 8 out of 10 staff members would actually benefit.” In the end, everyone played along. Student ambassadors from the ESP’R association even took it upon themselves to explain the initiative to cafeteria customers.

The study’s verdict: displaying a dish’s carbon footprint does not significantly influence food choices. Removing meat dishes once a week reduces the carbon footprint by 10%, but also leads to a drop in attendance. Changing prices, however, is highly effective. When the vegan option is priced 50 cents lower than the steak and fries alternative, the carbon footprint drops by 27%. This reduction climbs to 42% when the vegan dish is priced below €2 and the steak and fries at €8 — with no decline in cafeteria attendance.
“Contrary to the self-reported survey results, the study shows that in real-life settings, only financial incentives truly work,” Stefano says with a smile. “Consumer theory, which we teach our students, is fully validated… even though I would’ve liked to prove otherwise.”
The good news? In a post-study survey, 60% of cafeteria customers approved the introduction of bonus-malus pricing to reduce carbon emissions. “Even meat lovers vote for impact-driven policies.”

“Changing prices led to behavioral shifts in a domain — food — that’s deeply rooted in French culture. Imagine applying the same strategy to less emotionally charged goods like electricity or transportation: the impact would be even greater.”
To boost demand for eco-friendly products, consumers must be financially incentivized — a lesson worth reflecting on, for both public policymakers and businesses.

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