How Promoting Access-Based Consumption Provokes Overconsumption

Access-based consumption, such as car sharing or ride-hailing, is often promoted as a more sustainable alternative to ownership-based models, combining both society-related (e.g., sustainability) and self-related (e.g., cost savings) benefits. However, this promise of sustainability can backfire when consumers substitute lower-emission alternatives—such as biking or public transportation—with access-based services, a phenomenon we define as overconsumption. Across two laboratory experiments (n = 351; n = 388) and a field study (n = 167) in different mobility contexts, we demonstrate that communication strategies activating both self-related and society-related benefits—although effective in increasing participation—can unintentionally foster overconsumption. In contrast, activating society-related benefits alone significantly curbs this effect. We identify self-enhancement as the central underlying mechanism driving these effects in a dual role. While self-enhancement increases both participation and overconsumption, its impact is contingent on consumers' environmental identity. Specifically, self-enhancement promotes sustainable participation among individuals with higher environmental identity but encourages overconsumption among those with lower environmental identity. Our findings offer actionable insights for marketers, policymakers, and nonprofits by outlining communication strategies that maximize engagement while minimizing environmental harm in the promotion of access-based consumption.