This study aims to achieve a transition from prevailing consumerist behaviour towards responsible consumption, as outlined in the Sustainable Development Goals of the United Nations, it is crucial to understand the determinants of consumer behaviour in terms of sustainability. Social marketing can harness these determinants to encourage behavioural change towards more responsible consumption patterns. By constructing a model grounded in the Theory of Planned Behaviour (TPB), this study provides a framework for steering consumer behaviour in a more sustainable direction, specifically within the food sector, where the high frequency of purchase and short consumption cycles offer significant opportunities for impactful behavioural shifts.
By applying the TPB framework, this study aims to construct a model of sustainable consumer behaviour that identifies key behavioural determinants and their interrelations. Initially, the original TPB model is validated using Partial Least Squares Structural Equation Modelling, confirming its relevance in the context of sustainable behaviour. The model is subsequently extended by incorporating additional determinants, thereby increasing its explanatory power.
The validation of the original TPB-based model reveals that subjective norms, which reflect the influence of societal expectations, represent the most significant predictor of sustainable consumer behaviour. The inclusion of two further determinants – education and lifestyle – enhances the model’s predictive capacity. Among these, the strongest direct association is found between education and lifestyle, with education exerting an indirect effect on actual consumer behaviour. These newly integrated variables complement – the original TPB model and offer valuable insights into consumer decision-making processes. They also provide practical entry points for social marketing interventions designed to promote behavioural change towards sustainable and responsible consumption.
While the geographical scope of the dataset (focusing on consumers in the Czech Republic) represents a limitation, it also points to a promising direction for future research. Further, as is typical of TBP methodologies, the results are based on data provided by the respondents themselves. Future research could benefit from incorporating objective longitudinal data, which would allow for further validation of these psychological constructs.
To foster socially accepted sustainable consumer behaviour, individuals should be encouraged to make gradual changes in their habits. This transformation can be facilitated through targeted consumer education encouraging the adoption of sustainable practices, such as waste reduction and healthier lifestyle choices. The extended TPB-based model can serve as a practical tool for social marketers, uncovering behavioural dimensions that can be strategically addressed to stimulate positive change. Nevertheless, education alone is insufficient to ensure sustainable consumption. It must lead to a transformation in lifestyle, which, when combined with social influence, results in observable changes in consumer behaviour.
The identified model highlights the significant influence of subjective norms in shaping real behaviour. This determinant, which represents perceived social pressure, emerges as the strongest predictor of real sustainable behaviour in both the original and extended models. These findings underscore the powerful role of social influence in shaping individual consumer choices.
This paper presents a unique implementation of additional determinants of actual sustainable consumer behaviour within the TPB framework: specifically education and lifestyle. The findings demonstrate the indirect effect of Education on Real behaviour, mediated through the direct influence of lifestyle. In doing so, the study identifies key mechanisms by which consumers can be guided towards adopting more sustainable consumption practices.
