Examining innovative designs of agri-environmental schemes in Europe: A case comparison of impact pathways

Agri-environmental schemes (AES), a subtype of payments for ecosystem services (PES), aim to address Europe's environmental and climate objectives by incentivising farmers to maintain or shift to farming practices that deliver additional ecosystem services (ES). We develop a theory of change (ToC) for AES, reviewing nine European case studies at different implementation stages, yet all featuring innovative contract solutions to increase ES provision (e.g., water quality, pollination) and enhance bird and grassland biodiversity. Mirroring ecosystem and geographic variety across Europe, we analyse observed strengths and weaknesses in designing, implementing, and evaluating AES, and flag emerging research gaps. Using the comparative case study (CCS) method to analyse case-specific secondary data, we highlight the importance of local contextualization and management customization across landscapes, differentiating contract types to target variable farmer groups. Some regionally implemented schemes outside the EU's Common Agricultural Policy (CAP) framework emphasize trust-building and prove well-tailored to local conditions. New result-based schemes may achieve both farmer uptake and incremental ES delivery, depending on ES types and costs. Spatial coordination incentives (agglomeration bonuses and thresholds) stimulate farmer uptake, but their cost effectiveness remains undocumented. Collective AES schemes can work well when collaborative traditions and accumulated social capital are ex-ante present. Mixing incentive policies with regulatory threat may boost AES uptake. Generally, high opportunity costs among intensively producing farms and complex administrative processes constitute key obstacles hampering AES success. Current research mostly measures AES success in terms of farmer participation (ToC outputs), while rigorous environmental impact evaluations (ToC outcomes and impacts) are essentially lacking. Addressing the identified obstacles and research gaps might enhance AES effectiveness, but also provides more educated perspectives on realistic potentials for AES to support European sustainability goals.