Objectives: Disposal of designated wastes that are radioactive contaminated by the Fukushima nuclear accident is a primary issue in Japan since the candidate site has not been decided yet for over five years. Siting repositories for such risky wastes often faces an opposition from residents. This study examined the determinants of public acceptance of siting a repository for designated wastes, focusing on procedural fairness and trust. Although procedural fairness and trust have revealed the significant factors on public acceptance, affect sometimes alters the acceptance. Therefore, affect might detract the effects of procedural fairness and trust. The study presumed that affective reaction moderates the effects of procedural fairness and trust on public acceptance. To examine the presumption, the study implemented a hypothetical scenario experiment that manipulated two factors: a reflection of public opinions (voice) as an antecedent of procedural fairness and similarity value to authority as a component of trust.
Method: 289 people participated in the web-based experiment. Participants were randomly assigned to one of four conditions: voice (high vs. low) × similarity (high vs. low) factorial design associated with acceptance of siting investigation for the designated wastes. The experiment measured affective reaction to the siting, and evaluations of procedural fairness, trust, public acceptance in the decision-making process.
Results: Process analyses were used to test the moderating effect of affective reaction to the mediated process of the manipulations (i.e. voice and trust) through evaluations (i.e. procedural fairness and trust). Results indicated that voice determined public acceptance by way of evaluation of procedural fairness. Moreover, similarity determined public acceptance by way of evaluation of trust. In addition to the direct effects of affective reaction to procedural fairness, trust and public acceptance, the interactive effect of affective reaction × similarity on trust was found. A moderated mediated test indicated that the effect of similarity on public acceptance was strengthened when the affective reaction was negative. However, the interactive effect of affective reaction × voice on procedural fairness was not found.
Conclusion: The results showed that trust based on similarity was susceptible to affect, while the process of voice through procedural fairness to public acceptance was not susceptible to the affective reaction. Procedural fairness based on the opportunity of voice might be a stable determinant of public acceptance regardless of people’s affect. This study suggested the significance of procedural fairness beyond affective reaction for the public acceptance of siting a facility for designated wastes.