The Impact of International Conservation Agreements on Protected Areas: Empirical Findings from the Convention on Biological Diversity Using Causal Inference

Although 30 years have passed since the Convention on Biological Diversity (CBD) was adopted in 1992, few attempts have been made to evaluate its impact on protected areas. This study investigates the relationship between participation in the CBD and conservation effort in member countries, using an original dataset of 169 countries from 1992 to 2015. Our measure of conservation effort is the percentage of a country’s terrestrial area under protection, which is the primary mechanism for achieving the CBD’s conservation as distinct from its sustainable use or access and benefit-sharing objectives. We consider how protected area expansion relates to membership of the CBD, and a set of socio-economic and political variables that measure both the opportunity cost of conservation and national responsiveness to the demand for public goods. We find a positive and significant relationship between the area under protection, membership of the CBD, and a dummy for the Aichi biodiversity targets-Nagoya protocol. We also find that the area under protection is negatively related to measures of economic development and education (proxies for the opportunity cost of conservation), and positively associated with forest area (a proxy for species richness and endemism). We conclude that, at least for this measure of conservation effort, the CBD has had a significant impact, albeit moderated in predictable ways by the opportunity cost of conservation.