Mapping Layers of Sustainability Consciousness in Food Consumption Using the Item Response Theory (IRT) Approach

Understanding how consumers commit to sustainability in their food choices requires attention to both widely shared values and the points where commitments differ. Drawing on Item Response Theory (IRT), this study examines survey data from more than one thousand consumers to map a continuum of sustainability consciousness. Traditional regression approaches treat all motives as equal; however, the IRT method's main advantage is to highlight which attitudes most distinguish consumers and where the boundaries lie between superficial agreement and deeper commitment. The main research questions are (i) which consumer motives most effectively differentiate levels of sustainability consciousness; (ii) what makes commitments that widely agree become stronger and more demanding endorsements; and (iii) how do the education and gender characteristics shape variation along the continuum of sustainability consciousness. The results show a layered structure. Trust in farmers and assessments of freshness and taste serve as broad entry points, while social influence and ecological concerns result in stronger differentiation. Collective support for local farmers appears to be the most demanding form of commitment. Education and gender do not shape these orientations, suggesting that social characteristics systematically structure sustainability consciousness. For industry and research, product development and communication strategies can be based on widely shared entry points such as taste and trust, while targeted interventions are needed to promote stronger ecological and collective commitments.