This collection of original essays by economists, biologists and political scientists has a common theme: that protecting species at risk while safeguarding social order is a policy challenge that entangles biology, politics, and economics. Nearly 1200 species are now listed as endangered or threatened under the Endangered Species Act (ESA) of 1973; only twelve have been removed from the list. Attempts at species recovery on public and private property lead the authors to examine the political realities that define the debate: who should pay the costs and receive the benefits, and how interest group behavior affects the nature of endangered species protection. Although the ESA directs administrative agencies to list and protect species following scientific priorities, the collection addresses the economic choices that still must be confronted. These range from the protection potential of private markets to the design of incentive schemes to encourage conservation by private landowners.