Integrating TPB and NAM to explain organic aquaculture transition intentions: evidence from Thanh Hoa, Vietnam

Purpose This study examines aquaculture households' intentions to transition to organic aquaculture in Thanh Hoa, Vietnam. Building on the theory of planned behavior (TPB) and the norm activation model (NAM), the study distinguishes perceived benefits into economic and non-economic dimensions, incorporates moral norm as an internal moral consideration and examines the moderating role of subjective norm in the relationship between moral norm and transition intention. Design/methodology/approach A quantitative research design was employed using survey data collected from 323 aquaculture households in Thanh Hoa, Vietnam. The proposed model was tested using partial least squares structural equation modeling (PLS-SEM) to examine the hypothesized direct, indirect and moderating relationships. Findings Perceived economic benefits, perceived non-economic benefits, subjective norm, perceived behavioral control and moral norm are positively associated with transition intention, with moral norm showing the strongest association. Moral norm is positively associated with perceived non-economic benefits but not with perceived economic benefits, indicating a distinction between the two dimensions of perceived benefits. In addition, the interaction between subjective norm and moral norm is positive and statistically significant, indicating that the positive relationship between moral norm and transition intention becomes stronger as subjective norm increases. Research limitations/implications This study is limited by its cross-sectional design and its focus on transition intention rather than actual behavior. The model also does not fully account for socio-demographic, structural and institutional factors that may affect the intention–behavior gap. Future research should use longitudinal data, incorporate these external constraints, examine mechanisms that may bridge the intention–behavior gap and test the model across different geographical contexts. Originality/value This study extends behavioral research on organic aquaculture in three respects. First, it distinguishes perceived economic and non-economic benefits to provide a more differentiated understanding of benefit-related considerations associated with transition intention. Second, building on TPB and NAM, it examines subjective norm not only as a direct predictor of intention but also as a moderator of the relationship between moral norm and transition intention. Third, by applying this framework to aquaculture households in Thanh Hoa, Vietnam, the study provides context-specific insights for policymakers, extension agencies and other stakeholders in designing policies and support programs for organic aquaculture transition.