There is no adequate inventory of population size and distribution of most of the world's animal and plant species and lower taxa. Furthermore, populations are rarely static and continue to change in response to both natural and man-made factors. Thus clearance today for public works or industrial projects can be reversed tomorrow as new information becomes available. Lacking assurance that a project can be completed without new endangered species surfacing places an untenable constraint on the commitment of dollars for new long-term programs.
As a consequence of the absence of data, studies to determine occupied range, population levels, and habitat requirements of specific endangered species must be conducted on each project area. The direct costs of these studies are the responsibility of the project applicant. The time consumed results in project delays which can become a major expense item. Additional economic impacts are inherent in construction modifications and subsequent project operations intended to accommodate an endangered species.
Finally, the withdrawal of natural resources to support endangered species can conceivably reach a point where the squeeze on other societal programs becomes unacceptable.
Spencer, Donald A.
"The law and its economic impact,"
Great Basin Naturalist Memoirs: Vol. 3
, Article 5.
Available at: http://scholarsarchive.byu.edu/gbnm/vol3/iss1/5