摘要:The challenge of using limited funds to protect biodiversity has motivated much important research. One important line of work has been based upon the Noah’s Ark metaphor developed by Weitzman (1998). I summarize the main criticisms of that model and use those to develop heuristically a new variation of that model. That new policy ranking model includes ecological value and diversity as well as the economic benefits and costs and probability of successful protection that Weitzman used. I demonstrate the model with an example of two policies intended to enhance Keoladeo National Park in India, and conclude by discussing how the example highlights the importance of the interactions of all five of those aspects.