Let us buy sustainable! The impact of cash mobs on sustainable consumption: Experimental results

Cash mob is a practice where groups of people gather at local shops to buy a given product (usually with a strong sustainable feature) and make their decisions visible to the general public. With our paper we aim to assess the effectiveness of the cash mob as a behavioural tool and provide a better understanding of the behavioural triggers of consumers’ decision making process. We run a laboratory experiment where we mimic sustainable consumption and the cash mob treatment is embedded in a sequential game structure with/without an environmental frame. We find that the cash mob treatment has a positive gross effect, that is, the share of sustainable consumers is significantly higher in treated sessions. We also document a significant effect of expectations about the number of those eliciting a sustainable behaviour depending on participants’ previous choices. Our results suggest that cash mob-like mechanisms can help to solve social dilemmas like sustainable consumption with entirely private solutions (not based on punishment like taxes but on positive action), and with no costs for government budgets.