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 18 / 30 Interaction effect analysis Following the previous analysis, this study analyzed the moderating effects of the environmental psychological factors of climate change skepticism, guilt, and efficacy. Baron and Kenny’s [109] three-step test was used to check the variables and interaction terms, and the results were tested for the simple slope effect. The results showed that climate change skepticism, a moderating variable, had an interaction effect with materialism and emotion, which are independent vari- ables. Table 1 in S1 Appendix in support information lists the results of the interaction effect analysis. Figs 4 and 5 show climate change skepticism as a moderating variable. Fig 4 shows that as materialism increases, support for the plastic tax decreases. However, this effect is reinforced in groups with low climate change skepticism. In the high climate change skepticism group, increased materialism does not increase the support for the tax. These results sug- gest that climate change skepticism and materialism interact to create a negative attitude toward plastic taxes. Climate skep- ticism significantly moderated materialism-acceptance relationships, where materialistic individuals under high skepticism conditions showed particularly strong negative attitudes toward plastic taxes. This interaction supports motivated reasoning theory [24], suggesting that skeptical individuals use materialistic values to justify opposition to environmental policies.

Fig 5 shows that negative emotion, a component of the risk perception paradigm, interacts with climate change skep- ticism.. The skepticism-emotion interaction indicates that negative climate emotions have stronger positive effects on tax support among highly skeptical individuals, potentially representing cognitive dissonance resolution mechanisms. This finding extends Slovic et al.‘s [83] work on emotional responses to environmental risks and supports Kim et al’s [82] find- ings on negative emotions’ significant impacts on nuclear energy acceptance. Fig 4. Materialism*Climate change skepticism. https://doi.org/10.1371/journal.pone.0337327.g004