Purpose: This study investigates how behavioral economics principles influence consumer sustainability choices, with particular emphasis on nudging strategies and the attitudebehavior gap in environmental decision-making.

Design/methodology/approach: A qualitative interpretive study employing semistructured interviews with 35 consumers across diverse demographic and psychographic profiles. The research integrates behavioral artifacts collection with traditional interview methods, using an integrated theoretical framework combining Dual-Process Theory, Theory of Planned Behavior, Nudge Theory, Prospect Theory, and Social Norms Theory.

Findings: The study reveals four primary themes explaining sustainable consumption: dualsystem processing where automatic and deliberative systems compete in environmental choices; social norm activation and identity conflicts arising from peer influence and community expectations; choice architecture and contextual influences shaping sustainable behaviors; and temporal discounting and loss aversion dynamics that systematically bias decisions toward immediate costs over future environmental benefits.

Research limitations/implications: The qualitative approach limits statistical generalization, while the cross-sectional design restricts causal inference. Future research should examine longitudinal behavior change patterns and test intervention effectiveness across cultural contexts.

Practical implications: Findings inform policy design for sustainable consumption promotion, ethical marketing strategies incorporating behavioral insights, and consumer empowerment tools for bridging the attitude-behavior gap.

Social implications: The research contributes to understanding how individual behavior change can support broader sustainability transitions, addressing critical environmental challenges through consumer choice architecture.

Originality/value: This study provides novel insights into the psychological mechanisms underlying sustainable consumption decisions, offering an integrated theoretical framework for understanding and influencing environmental consumer behavior through behavioral economics principles.