The invisible alternative: How omitted options influence responsibility as a mechanism of spillover in green consumption contexts

Abstract Background Across spillover studies, participants' level of agency over initial behaviors is mixed. Restricting agency over a behavior may evoke reactance and be followed by attempts to restore choice freedom, potentially by denying responsibility for the initial behavior and exercising agency over a subsequent behavior, which is especially relevant in spillover contexts. Aims This research aimed to investigate the roles of agency and ascribed responsibility (AR) in the spillover process. Materials & Methods Two online experiments used coffee‐ordering scenarios (total N = 1752; all data collected in 2023). Study 1 examined the influence of assigned cup type (sustainable or conventional) on coffee choices. As a consequential behavioural‐dependent measure, participants chose either a conventional or sustainable coffee, the latter of which they were told would cost $0.25 of their $1 compensation. Study 2 used the same coffee scenario and dependent measure, but in addition to manipulating cup type, we also manipulated information about cup choice alternatives and agency over cup choice. Results Across both studies, AR mediated the relationship between cup type and coffee choice. Critically, the indirect effect of AR was moderated by denied agency: AR was higher for the conventional cup when participants were only informed about their assigned cup (Studies 1 and 2), leading to negative spillover. However, AR was higher for the sustainable cup when participants were informed about both cups, leading to positive spillover (Study 2). Discussion and Conclusion Implications for behavioural spillover and Psychological Reactance Theory are discussed.