Although social influence on consumers’ behaviour has been recognized and documented, the vast majority of empirical consumer studies about sustainable products considers mainly, if not only, individual characteristics (socio‐demographic attributes, individual environmental attitudes, etc.), to explain the decision to buy sustainable products. Making use of experimental methods, this paper studies the social influence that peer groups like colleagues, family and friends may exert in the decision to choose for environmentally friendly products rather than conventional ones. We also test for different types of social influence, in particular for ‘herd behaviour’ vs. ‘social learning’. In our experimental setting, the relevance of peer effects is corroborated. We find clear evidence for ‘herd behaviour’ and the data indirectly support the presence of ‘social learning’ effects. The results also suggest heterogeneous impact of specific social groups.

This paper reports on an experiment that tests for the existence of peer effects in consumers' willingness to pay (WTP) for sustainable products. More specifically, we investigate whether the premium for an eco-labeled laundry detergent is sensitive to receiving information about the premium paid by other members of one's social group. The information manipulations in the experiment test for two distinct types of social influence, i.e., conformist and payoff-biased transmission. We find strong empirical evidence for a conformist transmission. Participants informed about the positive premium paid by the majority of their peers reported a higher premium than individuals not receiving any information. This result shows that previous studies on the WTP for sustainable products, which explain premiums by attitudinal measures and sociodemographic traits, unwarrantedly provide an under-socialized account. The inclusion of social influence variables significantly increases the explanatory power of the model.In the last two decades, the supply of eco-products and eco-labels has emerged as a response to growing consumer demand for products that are regarded more sustainable. As a result, many studies have been conducted analyzing the willingness-to-pay (WTP) for products with social and/or ecological characteristics. The majority of these studies find that a large group of participants is willing to pay a relatively high premium for sustainable products, starting at an additional 10% extra for disposable products and reaching up to a 35% premium for ingestible products such as fresh meats, seafood, and fruits and vegetables (e.g.,