Are climate change perceptions related with plastic policy support? Effects of climate change skepticism, guilt, and efficacy on the acceptance of the plastic tax

PLOS One | https://doi.org/10.1371/journal.pone.0337327 December 29, 2025 10 / 30 For guilt moderation, moral self-regulation theory suggests that guilt amplifies value-behavior consistency by height- ening moral salience [99]. Studies show guilt strengthens the relationship between environmental concerns and policy support among high-guilt individuals [18]. Regarding efficacy, social cognitive theory indicates that self-efficacy enhances the translation of values into behavioral intentions when individuals believe their actions matter [30]. Research confirms efficacy moderates the environmental value-behavior relationship [100]. Based on those literatures, we propose specific hypotheses: H9a: Climate change skepticism negatively moderates the relationship between environmentalism and plastic tax support H10a: Guilt positively moderates the relationship between environmental values and plastic tax support H11a: Self-efficacy positively moderates the relationship between perceived risk and plastic tax support. Method section Data collection and ethical statement This study used nationally representative survey data for the analysis. A nationwide survey was conducted by a profes- sional polling agency from May 30 to June 3, 2022, with 1,571 adults aged 19 and above. Participants were recruited through a professional polling agency using stratified random sampling based on region, gender, and age demographics matching Korean population statistics. This study employed a nationally representative cross-sectional survey design

following established protocols [101]. A stratified random sample of 1,571 Korean adults (aged 19+) was recruited through a professional polling agency using proportional quota sampling by region, gender, and age. The web-based survey achieved a 95% confidence level with ±2.5% sampling error. The web-based survey was administered from May 30 to June 3, 2022. Survey links were distributed via text mes- sages and emails to eligible participants. The questionnaire employed block randomization to minimize order effects, with value measures, risk perception items, and planned behavior scales presented in randomized sequences across participants. Informed consent was obtained electronically before survey completion. The average completion time was approximately 15 minutes. This study was conducted in accordance with the Declaration of Helsinki principles and Korean ethical research standards. Ethical review exemption was granted under the Korean Bioethics and Safety Act (2005), Article 15 [2], which permits exemption for research meeting specific minimal risk criteria aligned with interna- tional standards. Our study qualified for exemption under multiple established categories. First, the research involved minimal risk to participants, defined as risk no greater than that encountered in daily life activities. Survey questions addressed standard psychological constructs (attitudes, values, perceptions) commonly used in social science research without sensitive top-

ics that could cause psychological distress. Second, our web-based methodology eliminated face-to-face contact, which under Korean regulations requires additional IRB oversight due to potential identification risks. The anonymous online platform ensured participant confidentiality throughout data collection, with no mechanism for linking responses to indi- vidual identities. Third, we collected no personally identifiable information as defined under Korean Personal Information Protection Act Article 23. Demographic variables (age, gender, education, income) were collected in categorical ranges without specific details that could enable individual identification. Despite exemption status, we implemented comprehensive participant protection protocols. Electronic informed con- sent was obtained from all participants before survey access, including clear information about study purpose, voluntary participation nature, estimated completion time, data usage intentions, and unconditional right to withdraw without penalty. Participants received explicit assurance that responses would remain anonymous and confidential, with data stored on secure servers using encryption protocols. No personal contact information was collected or retained, ensuring complete anonymity throughout the research process.