Auctioning approaches for ecosystem services-Evidence and applications

Auctions have attracted growing attention as bidding mechanisms for soliciting or allocating payments for a wide range of ecosystem services (ES). This paper reviews the latest scientific knowledge on ES auctioning approaches. Using systematically selected academic articles, we trace and discuss the development of ES auction literature across space, time, target ecosystem, and mechanism type. We integrate previous attempts to organize this body of work to produce a composite factor map of entry points to more specialized sub-literatures engaging with current issues in auc-tion design and implementation. The results show that most academic work focuses on reverse auctions, where land-owners bid their willingness to accept contracts to protect or promote ES provisioning, but we also locate several forward (i.e. beneficiaries bid their willingness to pay for ES) and mixed mechanisms. We critically analyze major ad-vantages and challenges for each approach, emphasizing issues related to transaction costs and accessibility for partic-ipants and agencies. Overall, our findings suggest that ES auctions have a robust track record but remain administratively and logistically challenging. Further investment in open-source tools, shared infrastructure, and other efforts to make auctions more accessible to researchers, agencies, and participants alike is strongly indicated.