Do eco-labels matter? Extending the theory of planned behavior with knowledge and brand origin image to explain the oat milk purchase intention among Gen Y and Gen Z consumers in Indonesia

Aim/purpose – This research investigates the factors influencing consumer purchasing intentions toward eco-friendly-labelled products, particularly addressing the limited understanding of the emerging plant-based milk sector, specifically oat milk. The study explores consumers’ knowledge of eco-friendly labelling and their perceptions of brand image origin among Gen Y and Gen Z Indonesians. Design/methodology/approach – This study employs an extended theory of planned behav- ior (TPB) model. The sample was selected using purposive sampling, with the criterion being Gen Y and Gen Z living in Indonesia. Data were collected through a structured questionnaire from 209 consumers in Indonesia and analyzed using SmartPLS4. Findings – The results indicated that subjective knowledge, attitude, subjective norm, and perceived behavioral control are the direct drivers of consumers’ intention to pur- chase oat milk. Additionally, this study found that brand origin image influences subjec- tive knowledge. The study found that attitude and subjective knowledge mediated the relationship between purchase intention and subjective norm. In contrast, objective knowledge weakened the relationship between the subjective norm and the intention to purchase oat milk. Research implications/limitations – This research provides valuable insights for man- agers to understand how knowledge and perceptions influence consumer intentions to- ward eco-friendly, labelled plant-based dairy products. A key limitation is that the sam- ple comprises only consumers of oat milk, which may limit the applicability of the re- sults to the broader plant-based dairy market. Originality/value/contribution – This research contributes originality by analyzing the moderating role of consumer eco-label knowledge and brand origin image within the specific domain of plant-based dairy products, providing new insights that have not been extensively discussed in previous research, particularly in the context of developing countries. Keywords: eco-labels, purchase intention, TPB, knowledge, brand origin image. JEL Classification: M31, L66, Q56.