Handbook of Biodiversity Valuation : A Guide for Policy Makers All societies depend on biodiversity and biological resources and policy makers are increasingly aware that development pressures are today generating unprecedented rates of biodiversity loss. The fact that biodiversity issues often receive low priority in policy decisions is at least in part due to problems involved in assessing its contribution to society these values defy easy description and quantification. What cannot be quantified or is difficult to monitor and evaluate is easy to disregard. The result is that biodiversity fails to compete on a level playing field in policy decisio