Study by the University of Bonn: “Nudges” encourage the purchase of products with higher husbandry standards

Gentle purchase incentives can lead customers to choose groceries with higher animal husbandry standards more often. A recent study at the University of Bonn at least suggests this. The researchers used two different animal welfare label posters as “nudges.” Each poster itself changed the consumer behavior of participants shopping in a virtual supermarket. The share of products with higher animal welfare standards in the shopping cart was highest when both posters were combined. Further studies have yet to clarify the extent to which the results can be transferred to real shopping situations. The study has been published in the Journal of Behavioral and Experimental Economics.

“Nudges” are measures that support people when making decisions – gently, without restricting their freedom of choice. For example, healthy or sustainable options can be highlighted so that they are given greater consideration in purchasing decisions.

In the current study, three researchers from the University of Bonn investigated how nudging can influence the purchase of groceries produced with animal welfare in mind. In Germany, there are various labels that provide information about the husbandry conditions of farm animals, such as the ‘Haltungsform’ label for meat and dairy products and the EU egg marking. They show how animal-friendly the farming conditions are.

850 participants on a virtual shopping trip

“We have now designed two different posters,” explains Leonie Bach from the Institute for Food and Resource Economics (ILR) at the University of Bonn. “Participants saw the first poster before entering the virtual supermarket: We used the slogan ‘More and more people in Germany opt for more animal welfare’ to highlight a social norm. The second poster hung above the shelves in the supermarket and explained what conditions the different husbandry levels represent using clear graphics. This poster thus mainly provided information on the animal welfare label.”

The ILR researchers recruited over 850 participants for an online experiment via a market research agency. They were able to shop in a virtual supermarket on their home computer. In addition to animal welfare products, products from conventional animal husbandry were also available – at market prices. The participants were randomly assigned to one of four groups: One saw neither of the two posters, a second exclusively saw the social norm poster, a third only saw the information poster above the shelves, and a fourth saw both posters.

Nudging appears to work – especially in combination

The result: “In our experimental study, both information and social norm nudges had a positive influence on the selection of products with higher animal welfare standards,” explains Prof. Dr. Monika Hartmann. The researcher heads the Department for Agricultural and Food Market Research at the University of Bonn and is a member of the Transdisciplinary Research Area (TRA) “Sustainable Futures.”

It was thus possible to significantly increase the purchase of animal welfare groceries through nudging. The combination of various messages appears particularly promising. “The crucial factor: The two measures do not influence each other; instead, their effects are additive and independent of each other,” says Leonie Bach. In practice, this means: Each measure acts on its own and can be used or omitted independently without changing the effect of the other.

However, the participants only made a hypothetical decision. They did not have to actually pay for the groceries and did not ultimately receive any real products. It remains unclear to what extent the results can be transferred to real supermarket visits. Overall, the results indicate that nudges can influence purchasing decisions in favor of higher animal welfare standards and can form part of a broader package of measures.

Funding:

The project was funded by the German Federal Ministry of Food and Agriculture (BMEL); Project executing organization: German Federal Office for Agriculture and Food (BLE); Funding code: 28N1800025

Publication: Leonie Bach, Monika Hartmann, Nina Weingarten: Two nudges, one goal: Promoting animal welfare in a virtual supermarket; Journal of Behavioral and Experimental Economics; https://doi.org/10.1016/j.socec.2026.102608