Can complementary currencies foster sustainability? A systematic review of the impacts of environmental complementary currencies

Growing financial needs for a sustainable transition have led to the development of green finance and citizen-led monetary innovations. These initiatives recognized the necessity of developing new forms of money regarding the environmental crisis, referred to as environmental complementary currency (ECCs). ECCs aim to generate environmental benefits by rewarding pro-environmental behaviors, funding green projects, encouraging short supply chains and circular economy, and increasing environmental awareness and knowledge within communities.Despite case studies highlighting ECCs' potential benefits, no comprehensive synthesis of their environmental impact exists. This paper addresses this gap by theoretically identifying ECCs’ environmental impact and inferring their actual magnitude through a systematic review. Searches conducted on Google Scholar, Scopus, and field-specific databases yielded a dataset of 35 empirical studies on ECCs’ environmental impacts, focusing on grassroots and emerging forms of complementary currencies, including digital and crypto-currencies. Schemes not designed to reduce the footprint of human activities were excluded. Findings suggest that ECCs can reduce their users’ environmental impacts by raising awareness and knowledge and promoting a shift towards environmentally sustainable consumption. Moreover, we cannot conclude that the localization effects associated with ECCs generate benefits. This paper highlights the limitations of existing research and suggests directions for future studies.