LETTER Biological vs. social, economic and political priority-setting in conservation Casey O’Connor 1 , Michelle Marvier 1,2 and Peter Kareiva 1,3 1 Environmental Studies Institute, Santa Clara University, Santa Clara, CA 95053, USA 2 Department of Biology, Santa Clara University, Santa Clara, CA 95053, USA 3 The Nature Conservancy, 217 Pine Street, Suite 1100, Seattle, WA 98101, USA *Correspondence: E-mail: mmarvier@scu.edu Abstract The most influential conservation priority-setting approaches emphasize biodiversity and threats when deciding where to focus investment. However, socio-economic and political attributes of nations influence the effectiveness of conservation actions. A combination of biological and sociological variables in the context of a Ôreturn on investmentÕ framework for establishing conservation priorities was explored. While there was some overlap between megadiversity nations and return on investment priorities, only a few countries emerged as high priorities irrespective of which factors were included in the analysis. Conversely, some countries that ranked highly as priorities for conservation when focusing solely on biological metrics, did not rank highly when governance, population pressure, economic costs and conservation needs were considered (e.g. Colombia, Ecuador, Indonesia and Venezuela). No priority-setting scheme is a priori superior to alternative approaches. However, the analyses suggest that attention to governance and return on investment may alter biocentric assessments of ideal conservation investments. Keywords Biodiversity, conservation NGOs, habitat protection, human population growth, megadiversity nations. Ecology Letters (2003) 6: 706–711 INTRODUCTION Faced with greater demand than resources, governments, international institutions and non-governmental organiza- tions (NGOs) must make difficult decisions about where to invest in conservation. To meet this challenge, ecologists have advocated a variety of systems for establishing global conservation priorities (Myers 1988, 1990; Bibby et al. 1992; Dinerstein & Wikramanayake 1993; Sisk et al. 1994; Mittermeier et al. 1997, 1998; Olson & Dinerstein 1998; Myers et al. 2000). Most prioritization schemes focus primarily on measures of biological value and threat. Although ecoregions are often compared when establishing conservation priorities, organizations must deal with the unique regulatory agencies, legal institutions and societies of individual nations. Obviously, nations vary enormously in political, social and economic conditions. Unstable govern- ance, lawlessness, war, high cost of operations and an absence of infrastructure can hinder well-intentioned and well-funded conservation efforts. Moreover, human activity, in a broad sense, is related to the degree of conservation threat (Kerr & Currie 1995). If conservation is considered as an investment of limited time and money, it is conceivable that some biologically high-priority locations may not, in fact, be a wise investment of conservation effort. We attempt here to explicitly incorporate economic and political factors into conservation priority setting at a global scale. We build on a handful of earlier studies that have incorporated socio-political indicators into priority-setting exercises (Sisk et al. 1994; Reyers et al. 1998; Reyers & James 1999). Specifically, a return on investment framework was applied, but in a flexible manner because it was not obvious how much weight should be given to biodiversity value compared with socio-political constraints. By examining six different return on investment formulations, countries that robustly warrant Ôhigh-priorityÕ status were identified, regardless of the details of the ranking index. METHODS Indicators for feasibility Data on social, economic and political factors that are likely to influence the feasibility and utility of practicing conservation within a country were compiled. One index each for governance, economics, population pressure and Ecology Letters, (2003) 6: 706–711 doi: 10.1046/j.1461-0248.2003.00499.x Ó2003 Blackwell Publishing Ltd/CNRS