Rethinking Sustainable Luxury Fashion: The Role of Serendipitous Sustainability in Second-hand Markets

The increasing normalisation of sustainable marketplace practices has enabled consumers to engage in sustainable behaviours without holding corresponding sustainable attitudes. Participation in second-hand luxury fashion markets often occurs in the absence of strong pro-sustainability beliefs. Building on attitude–behaviour gap literature, this study introduces serendipitous sustainability, defined as the enactment of sustainable behaviours that arise incidentally from social, structural, and market conditions rather than from internalised sustainability values. This research examines when and how consumers engage in second-hand luxury consumption without holding congruent sustainable attitudes. A literature-derived consumer typology informs an interpretive research design comprising 31 in-depth interviews with Generation Z and Millennial consumers of second-hand luxury fashion in New Zealand. Thematic analysis reveals that social context, sustainable attitudes (or their absence), self-efficacy, and sustainability knowledge interact dynamically to shape sustainable behaviour. We conceptualise a cyclical Social Determinants of Sustainable Consumption (SDSC) model grounded in these themes, positioning social context as a central, compensatory force that can bridge gaps between attitudes and actions. The model explains how sustainable behaviours can be initiated and sustained in the absence of sustainable attitudes through reinforcing feedback loops between social context, self-efficacy, and behavioural practice, captured by the concept of serendipitous sustainability. Managerially, the SDSC proposes a framework for identifying dominant behavioural pathways and activating social and structural determinants through targeted marketing initiatives. The findings suggest that the future of sustainable retail may depend less on changing consumer attitudes and more on designing marketplaces where sustainable actions are socially appealing, normalised, and structurally supported, allowing serendipitous sustainability to become an everyday practice.