Abstract
We demonstrate that adding eco-friendly components to offerings improves sustainability judgments, whereas reducing or removing such components—despite potential sustainability gains—receives little recognition. We call this asymmetry the sustainable additive bias . Across nine studies, including a field and a lab experiment, we demonstrate the existence of this bias and uncover its underlying mechanism and boundary conditions. We show that companies are judged more sustainable when they add, rather than subtract, eco-components. This asymmetry is specific to eco-friendly components: consumers recognize the sustainability benefits of removing traditional, less environmentally friendly components. The bias arises because additive changes signal greater environmental effort on the part of the company and is attenuated by prototypicality—that is, the extent to which a component represents a typical example of sustainability. Overall, our findings highlight how environmental cues can distort sustainability judgments and favor additive changes that may be counterproductive to genuine sustainability. We describe the implications of this bias and actions to reduce it.