Analyzing the effects of green lifestyle promotion and activism on willingness to pay a premium via parasocial relationships and trust: An integrated stimulus-organism-response model incorporating signaling theory and parasocial interaction theory

Abstract

Purpose: This study investigates how Green Lifestyle Promotion and Green Activism influence consumers’ Parasocial Relationship and Trust with Green Social Media Influencers and how these psychological states subsequently drive Willingness to Pay a Premium for sustainable products. Design/methodology/approach: A two-phase design was employed. Phase 1 conducted a bibliometric analysis by initially collecting 508 articles (2010 – 2025) using the SPAR-4-SLR protocol and subsequently analyzing 47 core articles via the TCCM framework to identify research gaps. Phase 2 applied a cross-sectional survey of 608 Vietnamese social media users who follow at least one GSMI, analyzed via PLS-SEM within a Stimulus-Organism-Response framework. Findings: Both GLP and GA positively influence PSR and Trust. GA exerts a stronger effect on Trust than GLP, suggesting that altruistic, non-commercial content is more effective in overcoming greenwashing skepticism. Both PSR and Trust are confirmed as positive drivers of WTPP. PSR fully mediates the effects of both content strategies on WTPP, whereas Trust mediates only the GA-to-WTPP pathway; the indirect path from GLP to WTPP via Trust was not supported. Practical implications: Green influencers should integrate activism-oriented content alongside lifestyle promotion to sustain credibility. Eco-brands are advised to prioritize partners who cultivate relational depth and trustworthiness over follower reach. Originality/value: This study is among the first to differentiate GLP and GA as theoretically distinct S-O-R stimuli, integrating Signaling Theory and Parasocial Interaction Theory as complementary lenses. By employing WTPP as a highcommitment outcome within Vietnam's emerging green consumer market, the study addresses key theoretical and contextual gaps in the green influencer marketing literature.