Developing the '0U Cup': Promoting ecological behavior through a cup-sharing service system based on the Comprehensive Action Determination Model and choice architecture

Background With the increasing international interest in and social awareness about plastic waste, Korea has also been focusing on the enforcement of disposable plastic cup regulations. In addition to government initiatives and tumbler use campaigns, studies for overcoming the limitations of existing approaches and inducing ecological behaviors should be pursued. Methods Based on theoretical considerations of the Comprehensive Action Determination Model (CADM) and choice architecture, five design strategies were derived. After comparative analysis of three cup-sharing cases in Germany, the United Kingdom (UK), and South Korea in terms of social and cultural influences, an integrated service design model, '0U (Zero You) Cup', was proposed. The study model was verified through a four-day pilot experiment of its action-inducing incentives and self-sustainability designed in the environment. Results Based 'circulation', 'familiarity', 'trust', 'cost', and 'transition' as the five strategies, the experiment showed a high return rate of 74.89% for the 0U cups, and demonstrated the possibility of the campus café circulation system using on-site individuals as both users and workers. Conclusions This study serves as a starting point for the establishment of an integrated service design model for replacing disposable cup consumption behavior. The proposed model is unique as it proposed five strategies reflecting the socio-cultural environment of South Korea, considered individuals of the community as the core value of the model's self-sustainability, and discovered CADM's situational influences, and choice architecture's 'default option' and 'bandwagon effect' as a theoretical framework to cope with people's habit of changing their instant choices. To selfsustainably implement the current model, 'trust' and 'cost' must be considered in the future.