This research aims to examine how green extrinsic and intrinsic motivations individually and jointly affect green purchase intention and actual behavior, drawing on the integration of self-determination theory and the theory of planned behavior. Based upon a sample of 4062 consumers in Vietnam, we methodologically adopted a polynomial regression with response surface analysis to shed the light on how a higher degree of eco-friendly consumption intention and behavior is synthesized from the balance between high green extrinsic and intrinsic motivations. Conversely, a large imbalance between green extrinsic and intrinsic motivations will lower the level of environmentally friendly consumption. Additionally, this study indicates that green purchase intention is the most important predictor of green purchase behavior, and that green purchase intention significantly mediates the insolated and joint effects of green extrinsic and intrinsic motivations on eco-friendly consumption behavior.

This study examines how retailers’ in-store green promotion influences consumers’ repurchase intention toward green food products in Vietnamese supermarkets. Although prior research has examined green perceived value, green trust, and green purchase intention, less is known about how retailer-driven promotion at the point of purchase is associated with repeat purchase decisions, particularly through value-based and trust-based mechanisms in emerging market supermarket settings. Drawing on signaling theory and consumption value theory, the study conceptualizes in-store green promotion as a set of retailer-provided signals that help consumers evaluate credence attributes of green food, and develops a model in which green trust and four dimensions of green perceived value—emotional value, conditional value, functional value, and social value—mediate the relationship between in-store green promotion and repurchase intention. Data were collected through a survey of 412 consumers who had previously purchased green food products from supermarkets in Vietnam. The model was tested using confirmatory factor analysis and structural equation modeling. The findings show that in-store green promotion has a positive direct effect on repurchase intention and significantly enhances green trust and all four dimensions of green perceived value. Green trust and the four value dimensions also positively predict repurchase intention. Mediation analysis indicates that the effect of in-store green promotion on repurchase intention is transmitted through both green trust and multidimensional green perceived value. The study contributes to green marketing research by shifting attention from general green communication to retailer-driven in-store promotion and by explaining green food repurchase intention through integrated signaling-based, value-based, and trust-based mechanisms.