Summary of: Kokkinou, A., Quak, H. & Mitas, O. (2026). “Leveraging fairness to nudge consumers towards more sustainable last mile delivery options.” Transportation Research Interdisciplinary Perspectives, 37, 101956.
Every time a consumer clicks “next-day delivery,” they make a choice with real urban consequences; more vans, more congestion, more emissions. Getting consumers to voluntarily choose slower, consolidated delivery is a persistent challenge for logistics service providers (LSPs) and retailers alike. This Dutch study tackles that challenge head-on, asking: can we nudge consumers toward greener options without damaging their satisfaction?
The researchers designed a vignette-based experiment with 355 students. This is a population skewed toward frequent online shoppers testing combinations of a delivery surcharge (€4.95 for next-day delivery) and three types of accompanying message: sustainability-focused, cost-focused, or generic. The sustainable alternative was simply waiting up to three days, enabling LSPs to consolidate deliveries and reduce trip frequency.
What works: price, decisively. The headline finding is unambiguous. Applying a surcharge to the faster, less sustainable option drove a near-total shift in behavior from just 6% of participants choosing to wait without any intervention, to over 95% choosing to wait when a surcharge was applied. The effect is described by the authors as almost switch-like, and it dwarfs every other intervention tested.
Messaging alone helps, but modestly. A sustainability-oriented message (without any surcharge) raised the probability of choosing the greener option to around 42%. A cost-oriented message achieved roughly 24%. Both effects are meaningful, particularly for retailers reluctant to introduce surcharges, since they work without any price friction.
The unexpected twist: don’t combine them. Here is where the study delivers its most counterintuitive result. When a surcharge and a sustainability message were presented together, the likelihood of choosing the green option actually fell slightly compared to the surcharge alone. The researchers attribute this to green skepticism — consumers becoming suspicious of being manipulated when commercial pricing is dressed up in environmental language. The same dampening effect appeared when cost-oriented messaging was combined with surcharges, suggesting a broader distrust of the company’s justifications rather than specifically anti-green sentiment.
Fairness is the mechanism. Using causal mediation analysis, the study confirms that perceived price fairness partially explains the relationship between surcharges and satisfaction. Surcharges do reduce satisfaction (a key concern for retailers), but improved perceptions of fairness buffer that effect. This means communication around surcharges still matters, just not in the way the researchers initially hypothesized.
For practitioners, the takeaway is clear: price incentives are by far the most powerful lever available. Messaging should be used carefully and separately, not layered on top of a surcharge, where it can backfire. And critically, improved financial performance from surcharges is not just commercially convenient; it creates headroom for LSPs to invest in broader sustainability measures. In a sector operating on thin margins, that reinvestment loop may matter as much as the behavioral nudge itself.
The study is solid but narrow. Key questions for further research are:
Sample: 355 Dutch students skew young, and price-sensitive generalizability to broader consumer populations is limited.
One delivery choice: The sustainable option is simply waiting longer. That is a low-bar test. Real-world choices (parcel lockers, pickup points, cargo-bike delivery) are more complex.
Short-term only: The experiment captures a single purchase moment. Whether nudges hold over repeated decisions isn’t tested.
Green skepticism unexplained: The backfire effect of the combined surcharge-plus-message is flagged but not investigated.
Supply-side absent: How LSPs actually implement and communicate these interventions operationally is left untouched.