<![CDATA[Younger generations have begun to change their purchasing behaviour in response to growing environmental concerns and global sustainability efforts. This research evaluates the eco-friendly shopping habits of Zoomers (born 1997–2012) and Millennials (born 1981–1996) in India. The research employs the Theory of Planned Behaviour (TPB) to analyse how the stewardship model, subjective norms, perceived consumer effectiveness, environmental attitudes and ecological values influence green product buying behaviour. A quantitative research design was adopted, and data were collected from 391 respondents across urban, semi-urban, and rural regions using a structured questionnaire. The relationship between the constructs were examined using structural equation modelling (SEM). The results indicate that environmental awareness (β = 0.558) has a strong positive influence on green purchasing behaviour, followed by social influence (β = 0.225). Environmental awareness is significantly driven by attitude towards the environment (β = 0.430) and ecological values (β = 0.356). Social influence is primarily driven by subjective norms (β = 0.338) and perceived consumer effectiveness (β = 0.187), whereas stewardship orientation has a negligible effect (β = 0.025). The model explains 50.7% of the variance in green purchasing behaviour (R² = 0.507), 51.1% in environmental awareness (R² = 0.511), and 28.4% in social influence (R² = 0.284). The findings confirm the presence of an attitude–behaviour gap, where positive environmental attitudes do not consistently translate into actual purchasing behaviour because of various influences such as price sensitivity and the non-existence of sustainable products. This study contributes to the literature by extending TPB through the inclusion of ecological and social mediators and by providing comparative insights into generational differences in an emerging market context. The results provide useful implications for marketers and policymakers to create focused strategies that encourage sustainable consumption.]]>
