Spillover in sustainable consumer behavior: a matter of commitment

Consumers express their commitment to environmental protection by engaging in a variety of environmentally protective behaviors. We thus suggest that strengthening consumers' commitment to environmental protection will cause behavioral spillover, which is the joint change in multiple environmentally protective behaviors. This idea differs from other spillover notions that draw on psychological processes that follow a change in a specific behavior. By reanalyzing data from a pre-post treatment-control quasi-field experiment with customers of a retail company in which one group was exposed to a multiple-component intervention over the course of 8 months, whereas the other was not, we corroborated a significant commitment gain in the experimental group (n = 81) that did not occur in the control group (n = 152). This commitment gain manifested in the expected spillover effect that mirrored the Rasch-model-implied likelihood gains in increasingly favorable behavioral expressions of people's commitment to environmental protection. This research complements existing models of behavioral spillover by providing theoretical and empirical arguments that strengthening consumers' commitment to environmental protection can result in spillover. In practical terms, focusing on people's commitment to environmental protection could thus be a promising avenue for directly promoting sustainable lifestyles.

© 2025 The Author(s). Journal of Consumer Behaviour published by John Wiley & Sons Ltd.

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