From endorsement to adoption: Investigating the moderated-mediation effect of celebrity-endorsed green advertising in India

This study examines how celebrity-endorsed green advertising (CEGA) influences consumers' green product adoption (GPA) through multiple psychological mechanisms and boundary condition using the framework of stimulus-organism-response (S-O-R). This research delves deep to understand the concept of the organism as a multi-dimensional psychological system which comprises of direct predictors such as awareness of green brands (AGB), motivation for green purchase (MGP), and perceived health benefits (PHB) while willingness to pay (WTP) acts as moderator variable. Applying partial least squares-structural equation modelling (PLS-SEM), the study tests the hypotheses with 694 valid responses collected in India while applying a purposive sampling technique based on a cross-sectional design through questionnaires with a 5-point Likert scale for each indicator variable. The results show that CEGA significantly increases all organism variables with the most significant effect on MGP (β = 0.575), followed by AGB (β = 0.415) and PHB (β = 0.331), confirming external stimuli activate internal psychological processes effectively. MGP is identified as the strongest predictor of GPA (β = 0.569, large effect), emphasizing motivation as the primary pathway through which stimulus translates to response. WTP has a negative direct effect on GPA (β = -0.108), meaning that the stronger the price sensitivity, the lower the effectiveness of positive behaviours. However, moderation analysis reveals a nuanced effect; WTP weakens the impact of AGB on GPA while strengthening the effect of MGP and PHB. This finding indicates that awareness is more critical for low-WTP consumers, whereas motivation and perceived benefits dominate under high-WTP conditions. Therefore, the study advances S-O-R theory related to green and sustainable marketing by showing that cognitive and motivational factors can affect sustainable and green consumption and also advises marketers and policymakers to motivate consumers about the importance of using green products and its health benefits in emerging economy.