12 Environmental policies are implemented in complex socioeconomic settings, where 13 numerous stakeholders hold different and potentially conflicting values. In addition to 14 being scientifically well-founded, the experts' recommendations on which these 15 policies are based therefore also need to be operational and legitimate. 16 Multi-criteria decision-analysis (MCDA) is often used to solve management problems, 17 but studies in the literature rarely place importance on the way stakeholders perceive 18 researchers' interventions (which implies a lack of legitimacy), and most managers 19 lack the skills to reproduce routinely the operations involved (which implies a lack of 20 operationality). We use MCDA methodology in a different approach: "meta-decision-21 analysis" (Meta-DA). As researchers, instead of striving to identify the best way for us 22 to solve managers' problems, we identify the actors (the decision-aid providers, 23 *Revised manuscript with changes marked Click here to view linked References