Cost‐effectiveness of public policy for the long‐term conservation of private lands: What is the deal?

[...]effects of long‐term private‐land conservation interventions remain understudied (Nolte, ), and most conservation organizations continue to report success in terms of total area protected or species range covered, not in terms of causal effect. In Massachusetts, USA, differences in the causal effects of land acquisitions and easements on forest cover and avoided development were found to be more driven by differences in threat than by differences in land cover change on protected parcels (Nolte, Meyer, Sims, & Thompson, ). Because threatened parcels are often more costly than remote lands, ignoring threat can bias protection toward low‐cost locations where protection makes little difference. Future empirical studies offering detailed accounts of diverse underlying incentives and institutions, full lifetime costs, and causal effects will be essential for building an insightful and representative global evidence base on the cost‐effectiveness of public policy instruments for private‐land protection.