Published by EH.Net (November 2014)

Eric L. Jones, Revealed Biodiversity: An Economic History of the Human Impact.  Singapore: World Scientific, 2014.  xxxiv + 257 pp. $99 (hardcover), ISBN: 978-981-4522-56-4.

Reviewed for EH.Net by Mark Kanazawa, Department of Economics, Carleton College.

Revealed Biodiversity is an ambitious attempt to tackle a big topic: the impact of human activity on long-term trends in biodiversity.  What makes this book of general interest to biologists and economists interested in the environment is the fact that there is a powerful prevailing wisdom out there — that ongoing economic growth is responsible for an inexorable, and perhaps universal, decline in non-human species, which is already being manifested in massive species extinctions and the likelihood of many more in the future.  The premise of the book is that an economic historian, taking a long-term approach, may be able to document and analyze trends in biodiversity to enable us to contextualize and critically evaluate a number of claims commonly made in public debates about biodiversity.  Properly done, such a book could be an important contribution to our understanding of the factors that influence biodiversity and the prospects for the future.

I need to say from the outset that I was prepared to be sympathetic to the arguments of this book.  As Eric Jones correctly points out, there are a great many simplistic, unfounded assertions about declining biodiversity out there.  The enduring notion that things were better in the good old days and that the earth is going to heck in a hand-basket often substitutes for critical thought.  Preservation at all costs is another persistent notion and economists, with their focus on tradeoffs and opportunity costs, are perhaps uniquely equipped to contribute productively to public debates.

Unfortunately, this book did not live up to the high expectationrs that this reader, for one, held out for it.  Consider, as the book does, wanting to make the following case.  Contrary to the beliefs of many (non-economists), policy regarding biodiversity involves tradeoffs — we simply cannot, nor should we necessarily want to, save everything.  Even if we did, economic development has highly complex and often unforeseeable impacts on wild populations, making it extremely challenging to evaluate its overall impact.  Sometimes its effect on certain populations is even positive.  Furthermore, it is likely that different forms of economic development at different points in time have widely varying impacts on wild populations.  Indeed, it is difficult to even know the basic facts concerning such fundamental questions as how much have wild populations declined over time, and how generalized has been the loss of species.  Answering these questions requires that we establish baselines from which to measure decline.  But baselines vary depending upon timeframe, and people are in general susceptible to believing that the appropriate baseline is “how things used to be.”  Furthermore, baselines are themselves very much a function of situational economic factors, which make it unclear whether you are measuring a trend or some cyclical fluctuation.  And anyway, the number of species out there is beside the point, as what is really important is our capacity to actually observe species in the wild (what the author refers to as revealed biodiversity).

What I like about this strategy is that it attempts to go beyond simplistic notions of biodiversity trends to take a more nuanced approach.  Instead of being saddled with asking the simplistic question — what is the human impact on non-human species — the question becomes under what conditions will the human impact be more (or less) adverse to non-human species?  Answering this latter question is likely to be much more useful for formulating practical policy regarding biodiversity.  I will add that I agree with Jones’ premise that much public debate about biodiversity is largely ahistorical, because many (most?) biologists and economists do not make explicit assumptions about exactly what they are measuring, over what period they are measuring, and from what starting point.  Here is a potentially fruitful area of inquiry for economic historians, in at least helping us to understand what data there is.

But herein lies an important interpretive point.  Regardless of the assumptions one makes, just about everyone would probably agree that the trends, whatever they turn out to be, have both secular and cyclical components.  The cyclical feature is evidenced by the recent (short-term?) recovery of some species from dangerously low levels, like the California condor, American bison, and the Minnesota grey wolf.  One way to interpret Jones is that he is focusing on the cyclical component when he argues that human impacts can cause some species (locally) to flourish.  But I suspect that taking the big picture outlook, many biologists and naturalists would not share the implied optimism about the future of biodiversity.  If the secular trend is inexorably downward, they might argue, what does it really matter that some species have enjoyed a temporary reprieve when, as Keynes might have put it, in the long run they are all dead?  And with ongoing economic growth, climate change, and the world population projected to increase to over nine billion by 2050, who can really doubt that without absolutely heroic measures, the secular declines are going to vastly dominate the cyclical fluctuations?

I need to emphasize that much of me appreciates and applauds the exercise that Jones went through.  But if secular dominates cyclical, then taking so much time and energy simply to document economic impacts on local baselines, over whatever period and under whatever economic conditions, seems somewhat misplaced.  It is a little bit like spending a lot of time identifying where the last peak of the business cycle occurred when the economy is slipping into a massive, sustained depression.  By the end of the book, I found myself believing Jones had spent too much time illustrating, and too little time systematically analyzing, the connection between economic activity and the health of local species.  As a result, it is not entirely clear what the practical take-away message is.  I am convinced that contained in the approach taken by the book are implications — important ones — for what sorts of policies to pursue, but the book itself provided me with too little sense for exactly what they are.

Perhaps it is best to view Revealed Biodiversity as a starting point for future studies of biodiversity that take seriously the mutual interaction between the economy and the surrounding environment.  In this respect, the book is in the best tradition of environmental histories by such authors as Patricia Limerick, William Cronin, Kathryn Morse, Mark Fiege and others, which examine the complex interplay between the economy, society, and the environment.  But future studies need to go much further in helping us understand the overall picture, the likely trends, and the nature of the human impact on non-human species.

Mark Kanazawa is professor of economics and former director of environmental studies at Carleton College in Northfield, MN.  His forthcoming book, Golden Rules, examines the origins of western water rights in the California Gold Rush.

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