Legislation to protect biodiversity

Agustín Pérez-Barahona, Eric Strobl, “Legislation to protect biodiversity”, Sustainable Future Policy Lab: Opinions, 2020-001.

In the natural sciences, considerable attention is given to the preservation of biodiversity and, in particular, to species extinction. As a matter of fact, species preservation is a key component of the biodiversity debate. In this respect, conservation biologists, nature conservationists, and wildlife managers explicitly pay considerable attention to endangered species and their possibility extinction. Economists are also concerned with biodiversity and extinction, but have mostly concentrated on the design and implementation of conservation policies subject to economic constraints.

Figure 1: Sea turtle egg smugglers case (No. 15cr2867-JLS),by Laura E. Duffy, Office of the United States attorney southern district of California, San Diego, California.

In the US estimates suggest that up to 539 species have become extinct over the past 200 years. Although there was a growing awareness of the extinction threat to a number of prominent species as early as the turn of the 19th century, prior to the Endangered Species Act in 1973 (ESA), there was no general protective legislation in place. Early calls for wildlife conservation emerged in the 1900s with the near extinction of the bison and the disappearance of the passenger pigeon. A number of specific legislation pieces followed, such as the Lacey Act of 1900, the Migratory Bird Conservation Act of 1929 and the Bald Eagle Protection Act of 1940. The first more comprehensive legislation passed was the Endangered Species Preservation Act of 1966, but while this act permitted the listing of native US animal species it provided for limited protection.

The ESA now, at least in theory, potentially provides extensive protection for species listed, including protection of critical habitat, implementation of a recovery plan, restrictions on take and trade, authorization to make land purchase or exchanges for important habitat and federal aid to State and Commonwealth conservation departments.  However, while over 2,400 species have made it on the endangered species list since the passing of the ESA only 28 have been delisted due to recovery, despite a current annual expenditure of over $US 1.5 billion. Of course in practise implementation of effective species recovery plans is not necessarily straightforward since habitats are not always easily defined, threats are often multi-faceted, monitoring can be difficult, and implementation can be costly both more generally and in terms of opportunity cost.

There exist a handful of studies that empirically examine the effectiveness of species protection legislation in aiding species recovery.  However, the evidence in this regard appears to be by and large negative. Importantly, though, all of these studies treat species as well as the legislation and recovery plans as homogenous in their analysis.  But, not only do species differ widely in the nature of their habitat and the threats thereto, as a casual perusal of current listed species will show, implemented recovery plans and legislation tends to be very species specific.  The existing results are arguably thus difficult to evaluate in terms of their implications for policy.

Innovatively moving beyond the current literature, two of our recent studies (Brei, Pérez-Barahona and Strobl, 2016 and 2019) analyse the effectiveness of species protection legislation, taking into account the heterogeneity of species as well as their habits and threats. This promising approach allowed us to provide an in-depth assessment of the current legislation and recovery plans. We were also able to identify true limitations and possible improvements of this type of environmental protection policies.


Brei M., A. Pérez-Barahona and E. Strobl (2019), “The Effectiveness of Protecting Species Through Legislation: The Case of Sea Turtle Lighting Ordinances”, American Journal of Agricultural Economics. https://doi.org/10.1093/ajae/aaz025

Brei M., A. Pérez-Barahona and E. Strobl (2016), “Environmental Pollution and Biodiversity: Light Pollution and Sea Turtles in the Caribbean”, Journal of Environmental Economics and Management, 77, 96-116.

Cite as:
Agustín Pérez-Barahona, Eric Strobl, “Legislation to protect biodiversity”, Sustainable Future Policy Lab: Opinions, 2020-001.

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