💻 computer science

Investigating the Effects of Eco-Friendly Service Options on Rebound Behavior in Ride-Hailing

This study investigates how different eco-friendly service options in ride-hailing apps affect consumer behavior, finding that certain options can inadvertently trigger "rebound effects" by making convenience-driven vehicle use feel more permissible.

Original authors: Albin Zeqiri, Michael Rietzler, Enrico Rukzio

Published 2026-02-12

📖 4 min read☕ Coffee break read

CC BY 4.0

Original authors: Albin Zeqiri, Michael Rietzler, Enrico Rukzio

Original paper licensed under CC BY 4.0 (http://creativecommons.org/licenses/by/4.0/). ✨ This is an AI-generated explanation of the paper below. It is not written or endorsed by the authors. For technical accuracy, refer to the original paper. Read full disclaimer

The "Green Halo" Effect: Why Being Eco-Friendly Might Actually Make Us Less Green

Imagine you are deciding whether to walk to a friend's house or call an Uber. It’s a short distance—maybe a 15-minute stroll. Usually, you’d walk to save money and stay active.

But then, you open the Uber app, and you see a little green leaf icon next to an "Eco-Ride" option. Suddenly, you think, "Well, if I take the electric car, I’m still being a good person for the planet. I might as well be comfortable and take the ride."

That, in a nutshell, is what this research paper investigated.

The Core Problem: The "Moral Get-Out-of-Jail-Free Card"

The researchers wanted to study a phenomenon called the "Rebound Effect."

Think of it like this: Imagine you buy a super-efficient, fuel-saving hybrid car. You feel so proud of your "green" choice that you decide to drive it much more often, even for tiny trips where you used to walk. Even though the car is efficient, you end up driving so much more that you haven't actually saved as much carbon as you intended. You’ve "rebounded" back to high consumption.

In the digital world, this happens through Eco-Friendly Service Options (EFSOs)—those little labels on apps that say "Green Delivery" or "Carbon Neutral Flight." The researchers feared these labels might act like a "Moral Halo." When we see that halo, we feel we’ve earned "moral credit," which we then "spend" by making other, less eco-friendly choices (like choosing a car over walking).

The Experiment: The Virtual Commute

The researchers set up a simulation for 75 people. They gave them 50 different trips to "decide" on. For every trip, the person had to choose: "Do I walk, or do I take a ride-hailing car?"

To see how different "green" labels changed behavior, they tested five different scenarios:

The "No Green" Option: Just regular cars.
The "Minimalist" (The Leaf): Just a tiny green leaf icon.
The "Math Teacher" (CO2 Stats): Telling you exactly how much CO2 you save in pounds.
The "Social Butterfly" (Social Proof): Telling you, "Most people this week chose the eco-option!"
The "Gamer" (Points): Giving you "Eco-Points" for choosing the green ride.

What They Found: The "Convenience Justifier"

The results were eye-opening. Here is the breakdown:

The Green Label is a Permission Slip: When people saw even a tiny green leaf, they were significantly more likely to choose a car instead of walking. The "greenness" of the car acted as a psychological shield, protecting them from the guilt of not walking.
The "Minimalist" was surprisingly powerful: Interestingly, the simple leaf icon was one of the strongest triggers for people to stop walking and start riding. Because it didn't give much detail, people could "fill in the blanks" with their own optimistic ideas about how much good they were doing.
Convenience is King: No matter how much "green" info was provided, the main reason people switched to cars was comfort and time. The eco-labels didn't change what people wanted (comfort); they just changed how people felt about getting it.
The "Gamer" failed to impress: The "Eco-Points" didn't really change behavior much. People weren't sure if the points actually meant anything for the planet, so they didn't use them as a moral excuse.

The Takeaway: How to Design a Better Future

The researchers aren't saying we should stop offering eco-friendly options—those are still great! Instead, they are giving a warning to app designers (like Uber or Amazon):

Don't let the "Green Label" become a "Get-Out-of-Guilt-Free" card.

If an app just puts a tiny leaf icon on a service, it might accidentally encourage people to drive more and walk less. To prevent this, the researchers suggest:

Be Transparent: Don't just show a leaf; show the actual, real impact. If the impact is small, be honest about it so people don't feel they've "saved the world" by taking a 5-minute car ride.
Watch the "Moral Balance": Designers need to realize that humans are constantly "balancing their books." If we give them a way to feel "good" (the green ride), they will immediately look for a way to be "lazy" (the car ride). We need to design interfaces that encourage real sustainability, not just the feeling of it.

Technical Summary: Investigating the Effects of Eco-Friendly Service Options on Rebound Behavior in Ride-Hailing

Problem Statement

As digital platforms increasingly integrate Eco-Friendly Service Options (EFSOs)—such as electric vehicle (EV) ride-hailing or carbon offsets—to reduce personal carbon footprints, there is a growing concern regarding rebound effects. In the context of Human-Computer Interaction (HCI), a rebound effect occurs when the introduction of an eco-friendly feature inadvertently encourages increased consumption or less sustainable behavior.

Specifically, the authors investigate whether the availability of EFSOs (and the eco-feedback used to promote them) provides users with "moral credit," allowing them to justify substituting zero-emission modes of transport (like walking) with higher-emission modes (ride-hailing). The research seeks to understand if these design interventions, intended to promote sustainability, paradoxically undermine environmental goals by making convenience-driven choices feel more ethically permissible.

Methodology

The researchers conducted an online within-subjects experiment ( $N=75$ ) using a simulated ride-hailing interface called "RidePal."

Experimental Design: Participants were presented with 50 trials (10 trials across 5 conditions) where they had to choose between walking and ride-hailing for trips ranging from 0.5 to 2.0 miles (approx. 0.8–3.2 km).
Independent Variables (EFSO Variants):
1. No EFSO (Control): Only standard gas-powered vehicles were available.
2. EFSO - Minimal: The eco-option was indicated only by a simple green leaf icon.
3. EFSO - CO2 Equivalency: Communicated raw $CO_2$ savings paired with relatable metrics (e.g., pounds of coal burned).
4. EFSO - Social: Highlighted the collective environmental impact of all passengers over the past week.
5. EFSO - Gamified: Awarded "Eco-Points" for selecting the eco-friendly ride.
Measures:
- Behavioral: The probability of choosing ride-hailing over walking (operationalizing direct rebound).
- Subjective: 7-point Likert scales measuring Perceived Moral Credit Loss and Perceived Environmental Impact.
- Qualitative: Free-text reflections to understand the rationales behind decision-making.
Statistical Analysis: A logistic mixed-effects (LME) model was used to analyze the binary choice (walk vs. ride) as a function of EFSO variant and trip distance.

Key Results

Facilitation of Rebound Behavior: The introduction of EFSOs significantly increased the likelihood of choosing ride-hailing over walking, particularly at distances where walking was perceived as becoming effortful (above ~1.05 miles).
Impact of Feedback Design:
- The EFSO - Minimal condition (leaf icon) produced the most significant shift toward ride-hailing uptake.
- EFSO - CO2 Equivalency and EFSO - Social also increased ride-hailing uptake for longer trips ( $1.35–2.0$ miles).
- EFSO - Gamified did not show a statistically significant effect on ride-hailing uptake.
- Crucially, richer eco-feedback did not necessarily amplify the rebound effect compared to minimal feedback, but it did not prevent it either.
Moral-Psychological Drivers: Qualitative analysis revealed that participants prioritized convenience and comfort (time and physical effort) above all else. EFSOs functioned as a moral buffer, allowing users to reconcile the tension between their desire for convenience and their environmental values. Choosing an "Eco Ride" made the decision to skip walking feel "less guilty."
Perception vs. Reality: While EFSOs reduced perceived moral credit loss, they did not always reduce the perceived environmental burden of the trip, suggesting users view them as "small but meaningful" contributions.

Key Contributions

Empirical Evidence of Rebound in HCI: The study provides rare empirical evidence that EFSOs in digital interfaces can trigger direct rebound effects by facilitating the substitution of zero-emission travel with motorized travel.
Identification of Design Risks: It demonstrates that minimal or ambiguous eco-labels (like a leaf icon) may be particularly prone to causing rebound effects because they allow for unconstrained, "generous" user interpretations of environmental benefit.
Theoretical Extension: The work extends the "rebound cube" framework into the HCI domain by highlighting how moral-psychological pathways (moral licensing/balancing) interact with interface design.

Significance and Implications

The study has profound implications for Sustainable HCI (SHCI) and the design of green digital services:

Design Transparency: Designers should avoid ambiguous eco-labels. To mitigate rebound, EFSOs should communicate the true magnitude of benefits (using absolute values or clear equivalencies) to prevent users from overestimating their positive impact.
Holistic Evaluation: Developers must evaluate EFSOs not just by their "uptake" (how many people click the green option) but by their net environmental impact, accounting for whether those clicks come at the expense of even greener behaviors (like walking or cycling).
Addressing Moral Balancing: Interface design should account for the fact that users use "green" features to justify "non-green" lifestyle choices. Designing for "moral integrity" rather than just "moral credit" is a critical future direction for sustainable interaction design.