The Effectiveness of the Endangered Species Act: A Quantitative Analysis
BioScience 55(4):360-367, April 2005
Martin F. J. Taylor, Kieran F. Suckling and Jeffrey J. Rachlinski
Population trends for 1095 species listed as threatened and endangered under the Endangered Species Act were correlated with the length of time the species were listed and the presence or absence of critical habitat and recovery plans. Species with critical habitat for two or more years were more than twice as likely to have an improving population trend in the late 1990s, and less than half as likely to be declining in the early 1990s, as species without. Species with dedicated recovery plans for two or more years were significantly more likely to be improving and less likely to be declining than species without. The proportion of species improving increased, and the proportion declining decreased, with increasing time listed throughout the 1990s, irrespective of critical habitat and recovery plans. On the basis of these results, we recommend increased funding for earlier listing of imperiled species and prompt provision of critical habitat and recovery plans.
 Martin Taylor (email@example.com), executive coordinator of the National Parks Association of Queensland, Australia
 Kieran Suckling (firstname.lastname@example.org, (520) 623-5252 x305), policy and biodiversity program director, Center for Biological Diversity, Tucson, Arizona.
 Jeffrey Rachlinski (email@example.com), Professor of Law, Cornell Law School, Ithaca, NY 14853-4901
For more information, contact Kieran Suckling