Epsilon Archive for Student Projects

Abstract

This thesis investigates the impact of a behavioural intervention - specifically, a nudge in the form of a “Green Shelf” introduced in a Swedish supermarket - on the sales of plant-based food products. The intervention reorganised plant-based alternatives into a single, visually distinctive shelf to enhance visibility and encourage more sustainable consumer choices. Drawing on behavioural economics and choice architecture theory, the study employs a quasi-experimental design using daily point-of-sale data and applies a Difference-in-Differences (DiD) framework complemented by an event study analysis. Five treated product categories (meatlike, not meatlike, vegetarian fish, tofu/tempeh, vegetarian charcuteries) are compared to a control group (legumes) over an eight-month period.
The findings suggest that while most treatment effects are statistically insignificant, meaningful patterns emerge over time. Notably, the meatlike category - the largest among those examined - shows statistically significant short-term gains following the intervention, highlighting the nudge’s effectiveness in the absence of festive disruptions. Across all categories, sales increase up to the festive season, followed by a noticeable drop persisting through January, and then a gradual rebound beginning in February. These temporal dynamics suggest that although the overall impact appears modest, the intervention may hold the potential for longer-term behavioural change, particularly when external seasonal factors are accounted for. The results also support the parallel trends assumption and illustrate the feasibility of implementing nudging strategies in real-world retail environments. Limitations include the absence of a geographically distinct control store and potential indirect treatment effects on the control group.
This study contributes to the growing literature on nudging and sustainable consumption by providing real-world evidence of a long-duration, low-cost supermarket intervention. Continued monitoring of the Green Shelf, still in place, may offer valuable policy insights into the long-term effectiveness of visibility-based nudges in retail environments.