But again, I can’t help mentioning how much more difficult our current task is. We would hardly have begun to place a value on biodiversity if we had known how many species there are. We’re supposed to put a value on them. In what terms?

When I looked into a jar, I was always a bit overwhelmed at first, so let’s not give up yet. Eventually, I’d decide to be systematic about my guess. I’d divide the jar into somewhat equal sections and try to do a rough count for one of them. Then, I’d multiply by the number of sections. Despite my lack of success, it’s a reasonable approach; we can call it the divide-and-conquer method. Economists and other policy analysts have adopted a similar method for valuing biotic resources. They usually try to estimate, however roughly, a value for one species (Fisher, 1981; Fisher and Hanemann, 1985). If they could assign a value to a few species, such as the snail darter, the Furbish lousewort, and the California condor, then we might average the values of those species and then multiply that average value by the number of species there are, if we only knew how many species there are.

All this averaging and multiplying will require that we use numerical values, so we might as well follow economists in trying to use present dollars as the unit of value. Before introducing the technical terms used by economists, let’s start with some ordinary concepts: species can have value as commodities and as amenities, and they can have moral value.

We’ll say that a species has commodity value if it can be made into a product that can be bought or sold in the marketplace. In this category, alligators have potential value in the manufacture of shoes, but they may also have indirect commodity value if it turns out that vinyl shoes stamped in an alligator pattern sell for more than plain vinyl shoes. Indirect value of this sort is especially important in the pharmaceutical industry, since many of our most valuable medicines are synthetic copies of biologically produced chemicals (Lewis and Elvin-Lewis, 1977; Myers, 1983).

A species has amenity value if its existence improves our lives in some nonmaterial way, e.g., when we experience joy at sighting a hummingbird or when we enjoy walks in the forest more when we sight a ladyslipper. Hiking, fishing, hunting, bird-watching, and other pursuits have a huge market value as recreation, and wild species contribute, as amenities, to these activities. Bald eagles, for example, have not only inspired the production of millions of dollars worth of Americana, but they also generate aesthetic excitement through a whole area that is blessed with a nesting pair of them.

Finally, species have moral value. Here, we begin to encounter controversy. Some philosophers would say that species have moral value on their own. They are, according to this view, valuable in themselves, and their value is not dependent on any uses to which we put them (Regan, 1981; Taylor, 1986). We will not be able to settle this issue. Suffice it to say that species have moral value even if that moral value depends on us. Here, Thoreau comes to mind. He believed that his careful observation of other species helped him to live a better life (Thoreau, 1942). I believe this also. So there are at least two people, and perhaps many others, who believe that species have value as a moral resource to humans, as a chance for humans to form, re-form, and improve their own value systems (Norton, 1984; Norton, in press).



The National Academies | 500 Fifth St. N.W. | Washington, D.C. 20001
Copyright © National Academy of Sciences. All rights reserved.
Terms of Use and Privacy Statement