Many environmentally relevant policy issues such as nuclear waste disposal, water management, climate change, and large-scale energy and transport infrastructures call for long-term solutions in order to be addressed sustainably. To counter a possible ‘presentist’ bias in political and administrative decision-making and to find appropriate and widely supported solutions, it has been suggested to open up public decision-making processes to organized stakeholders and individual citizens, working collaboratively to resolve conflicts, foster innovation, and incorporate local knowledge. To assess whether – and under what conditions – these promises of participatory and collaborative governance hold true, we analyze around 80 cases of public environmental decision-making processes with long-term policy implications. In particular, we examine the contexts, rationales, and process design features of these processes to explain their environmental (as well as economic and social) outcomes.

To this end, we identify relevant cases from the SCAPE dataset (https://doi.org/10.7802/2134) that was developed within the ERC project ‘EDGE – Evaluating the Delivery of Environmental Governance using an Evidence-based research design’. The dataset is based on a case-study meta-analysis and comprises 305 rigorously coded case narratives of public environmental decision-making. Of these, we identified around 80 cases with fundamental long-term implications. In a nested research design, we combine large-N comparative analysis – e.g. linear or non-parametric modeling, and Qualitative Comparative Analysis (QCA) – with more in-depth analysis of a small number of case narratives to complement overall patterns with causal process tracing. Doing so, we gain unique insights into the ways in which participatory and collaborative forms of decision-making help overcome short-termism and develop sustainable solutions to long-term environmental policy problems.