This study aims to analyze the role of socio-cultural factors in shaping consumers’ beliefs and behaviors, particularly in the context of sustainable consumption, which influences consumer perceptions, green purchasing decisions, and brand defense. Grounded in the Theory of Planned Behavior (TPB), this research presents a comprehensive model exploring ethnocentrism and altruism as key socio-cultural drivers affecting consumers’ perceptions of the marketplace, ultimately shaping their green purchase intentions and brand defense behaviors. By using a mixed-methods approach, the study integrates quantitative data (surveying 480 Vietnamese Gen Z consumers) and qualitative insights (gathered from 265 participants) to present the final results that highlight the strong influence of socio-cultural factors on green purchasing behavior and brand defense. Specifically, altruism and ethnocentrism, mediated by perceived marketplace influence and TPB components, play a crucial role in driving green purchase intention, green brand equity, and brand defense. Moreover, the study extends the TPB framework by illustrating how consumer beliefs turn into sustainable purchasing decisions and advocacy for environmentally responsible brands. These findings offer valuable contributions to academic literature and practical strategies for brands seeking to enhance their resilience and consumer support through sustainability initiatives. Thus, by understanding the mechanisms that drive consumer advocacy, businesses can develop more effective green marketing strategies that foster long-term engagement and brand loyalty among environmentally conscious consumers.
Tran et al. (Wed,) studied this question.