Why choosing sustainability is complex: Consumer cognition, motivation, and decision trade-offs

This dissertation investigates why sustainable consumption remains difficult to enact despite widespread environmental concern and increasing market availability of green alternatives. Moving beyond intention-based explanations, the present research conceptualises sustainable consumer behaviour as the outcome of decision-making processes unfolding within real-world contexts, and explains how environmental considerations enter decision processes, are cognitively interpreted, and are motivationally maintained within consumer decisions. Drawing on environmental psychology, behavioural economics, and marketing and strategy research, the dissertation develops an integrative decision architecture in which competing needs, market opacity, and bounded rationality interact dynamically to shape behavioural outcomes. Empirically, the thesis combines three experimental research projects conducted on large consumer samples across distinct consumption contexts, with particular attention to the climate change domain: multi-attribute product choice in fast-moving consumer goods, carbon-neutrality communication in wood products, and sustainable shipping decisions in e-commerce delivery. The studies employ between-subjects and conjoint experimental designs manipulating environmental attribute competition and representation, level of information disclosure, claims substantiation, informational and intrinsic motivational levers (education, tailoring and framing), and financial interventions of varying magnitude. Outcomes capture multiple dimensions of sustainable consumption, including relative attribute importance, claim comprehension, perceived greenwashing, purchase intention, and shipping choices. Findings show that environmental attributes struggle to influence preference formation when their environmental meaning and implications are difficult to access and interpret. Under conditions of market opacity, abstract claims may outperform substantively superior information through heuristic rather than analytical processing, increasing vulnerability to greenwashing and carbonwashing. Moreover, action-oriented interventions that activate intrinsic motivation and reduce psychological distance to environmental consequences significantly strengthen sustainable choices. By contrast, financial interventions produce non-linear effects, as poorly calibrated economic incentives may backfire through moral licensing and motivational crowding-out mechanisms. Across decision contexts, sustainability emerges as vulnerable at different stages of the decision process: when environmental attributes fail to enter choice competition, when green claims are difficult to interpret under informational opacity, and when motivational interventions interact with competing short-term goals. Overall, the dissertation advances a process-based account of sustainable consumption, demonstrating that promoting sustainability requires designing choice contexts in which environmental considerations become cognitively usable, epistemically interpretable, and motivationally compatible with actual decision-making dynamics and market conditions, with important implications for both firms and public policy.