Ecological Modelling, 38 (1987) 1-7
Elsevier Science Publishers B.V., Amsterdam - Printed in The Netherlands
TOWARD AN ECOLOGICAL
ECONOMICS
ROBERT COSTANZA
Coastal Ecology Institute, Center for Wetland Resources, Louisiana State University,
Baton Rouge, 1_,,4 70803 (U.S.A.)
and HERMAN E. DALY
Economics Department, Louisiana State University, Baton Rouge, LA 70803 (U.S.A.)
ABSTRACT
Costanza, R. and Daly, H.E., 1987. Toward an ecological economics. Ecol. Modelling, 38:
1-7.
Integrating ecology and economics is increasingly important as humanity's impact on the
natural world increases. Current paradigms in both fields are too narrow (and seem to be
getting narrower). This paper introduces and summarizes this special issue of Ecological
Modeling devoted to ecological economics. There are eleven papers (including this one) that
cover most of the important theoretical issues involved (applied papers are left for a future
volume). These issues are: (1) sustainability; (2) inter- and intra-species distribution of
wealth; (3) discounting and intergenerational justice; and (4) dealing with non-monetized
values, imprecision, and uncertainty. This collection is seen as a hopeful first step toward a
true synthesis of ecology and economics that could lead to better management of renewable
and non-renewable natural resources and a sustainable future.
NEED FOR AN ECOLOGICAL ECONOMICS
T h e m a i n i m p e t u s for this special issue is the h y p o t h e s i s ( s o m e w o u l d say
o b s e r v a t i o n ) that c u r r e n t e c o n o m i c p a r a d i g m s h a v e some serious s h o r t c o m ings w h e n it c o m e s to dealing with n a t u r a l resources. T h e r e l e v a n t w o r d h e r e
is serious. N o e c o n o m i c s y s t e m or b o d y of ideas to a n a l y z e a n d c o n t r o l it
c a n b e perfect. But m a n y e c o n o m i s t s believe that the r e m a i n i n g i m p e r f e c tions n e e d ~aot b e cause for concern. F r e e m a r k e t e e r s believe that externalities are u n i m p o r t a n t a n d that the system can b e i m p r o v e d b y giving the
m a r k e t a n even m o r e free (but still invisible) h a n d . H a r d - l i n e M a r x i s t s
c o n t e n d that b e t t e r p l a n n i n g a n d political e d u c a t i o n will solve a n y r e m a i n ing (minor) p r o b l e m s .
A s e c o n d i m p e t u s is the o b s e r v a t i o n that ecological p a r a d i g m s t e n d to
ignore h u m a n cultural b e h a v i o r as an object of direct study. Ecologists are
generally concerned with predicting the impacts of human activity on
natural ecosystems, but not with understanding and predicting human
behavior in the context of natural ecosystems.
The authors in this volume share the view that the remaining problems
are very serious, and that fairly elaborate modifications to existing paradigms are necessary to address them. They cover a wide spectrum as to
exactly what the major issues and problems are, however, and how we might
go about rectifying them.
In this introduction we summarize the c o m m o n threads running through
the papers and put them in a larger context. We also mention a few
additional topics that do not appear in any of the papers. We title this
chapter: 'Toward an ecological economics' because the strongest thread
linking these wide-ranging papers is the idea that a certain broadening of
boundaries and perspectives needs to occur. Ultimately, we think this means
that ecology and economics must be more fully integrated if either is to deal
adequately with man's use of natural resources. This special issue is a
hopeful step toward that synthesis.
MAJOR ISSUES, PROBLEMS, AND SOLUTIONS
Concern about natural resources has a long history in economics, but it
has gotten short shrift in the 20th century as economists turned their
attention to other topics. The classical economists of the 18th century were
much more concerned with man's dependence on and interaction with
nature than their contemporary counterparts. In this special issue of Ecological Modelling, CLEVELAND gives an historical account of ecological/biophysical models from the classical economists to the present. There is much
here that is useful to remember and reiterate, and modern energy analysts
c a n be seen as proposing a more technically sophisticated revival of many of
these early ideas. CHRISTENSEN concentrates on the parallels and contrasts
between the classical economists, modern Marxist economists and modern
energy analysts.
The problems that result from ignoring man's interdependence with the
natural world can be defined in many ways. The sections below summarize
the major themes of the papers and provide some additional perspectives.
Sustainability: maintaining our life support system
The most obvious danger of ignoring nature in economics is that nature is
the economy's life support system, and by ignoring it we may inadvertently
damage it beyond repair. Several authors stress the fact that current economic systems do not inherently incorporate any concern about the sus-
tainability of our natural life support system and the economies which
depend on it. PEARCE discusses the reasons for the inability of existing forms
of economic organization (free market, mixed, planned) to guarantee sustainability. He then lays out what he views as the necessary conditions for a
sustainable, "ecologically bounded" economy. In his view the issue of
sustainability is intimately connected with the issue of justice (both within
species, between species, and between present and future generations) since
justice in this context ultimately implies sustainability. HUETING attempts to
apply some of these principles in order to quantify their economic implications. He concludes that saving the environment is not only economically
possible, but also necessary for ensuring sustainability.
Intra- and inter-species distribution of wealth
Wealth is ultimately the capacity to support life and the enjoyment
thereof. Therefore it is not really fanciful to think of sharing wealth in this
sense with other species or with future beings. In animal populations all
members have roughly the same 'standard of living' or level of per-capita
resource use. Nor does that use rate change over time. Of course there exists
territoriality and dominance hierarchies, so animal populations are not
totally egalitarian. But they are not divided into social classes in which some
have vastly more access to resources than others. For animals, respecting
carrying capacity is mainly a matter of limiting population, with per-capita
resource consumption levels remaining relatively constant and uniform. Of
course for humans per-capita resource use varies greatly among social
classes and is not constant over time. Consequently the issue of sustainability is not simply a matter of controlling numbers (although that cannot be
omitted), but also includes the issues of sufficiency and equity of distribution. Staying within carrying capacity for humans involves not only population control, but also consumption control and distribution control. None
of these are 'automatically' handled by free markets, nor are they popular
topics. Modern economics has little to say about justice and even less about
sufficiency, as PEARCE points out. HUETING considers the implications of
scenarios that give explicit priority to the environment and to long-term
considerations and shows them to be both practical and necessary. In
general, however, our authors only scratch the surface of these important
issues.
Turning from intra- to inter-species distribution of 'wealth' or carrying
capacity, it is clear that modern economics has declared that our species
should get an ever increasing share. This presumption leads to problems in
that it ignores the instrumental value of other species to us in maintaining
life support systems, and it ignores the intrinsic value of other species. The
issue of instrumental value of other species arises frequently in these papers.
Energy analysts calculate a form of intrinsic value based on the 'degree of
organization' or embodied energy of things (including living things). There
are practical and theoretical problems with this sort of calculation but the
idea that things can have some value independent of human perception of that
value is foreign to modern economics. To the average economist if a tree
falls in the forest, it not only makes no sound, but it has no value unless
there's a market in which consumers can reveal their preferences for timber.
While the market can be a powerful and useful tool for allocating resources,
one can think of many examples where humans have misperceived the value
of natural resources (i.e. wetlands) until it was almost too late. Some notion
of intrinsic value must therefore be introduced as a check on human
perceptions and to allow us to study the economies of nature which do not
include humans.
Discounting, intergenerational justice, and the time delay trap
Intergenerational justice is a strong motivating force in many of the
papers. Its close connection to sustainability has already been noted. Often
the present vs. future issue is thought to be objectively decided by discounting. But discounting at best only reflects the value of the future (all species
in the future) to the presently existing members of one species, ours. The
value of future life to the future beings themselves does not enter the
calculation at all. GOODLAND and LEDEC,and PEARCE,examine some of the
anomalies associated with discounting. It is worth emphasizing here that
discounting is simply a numerical way to operationalize the value judgment
that: (a) the near future is worth more than the distant future, and (b)
beyond some point the worth of the future is negligible.
Most economists tend to treat discounting as rational, optimizing behavior based on people's inherent preferences for current over future consumption. However, there is evidence that discounting behavior may be symptomatic of a kind of semi-rational, suboptirnizing behavior known as a
'social trap'. A social trap is any situation in which the short-run, local
reinforcements guiding individual behavior are inconsistent with the longrun, global best interest of the individual and society (Platt, 1973; Cross and
Guyer, 1980; Costanza, 1987). We go through life making decisions about
which path to take based largely on the 'road signs', the short-run, local,
reinforcements that we perceive most directly. These short-run reinforcements can include monetary incentives, social acceptance or admonishment, and physical pleasure or pain. Problems arise, however, when the road
signs are inaccurate or misleading. In these cases we can be trapped into
following a path that is ultimately detrimental because of our reliance on the
road signs. Discounting allows us to give too little weight to the future (or
other species, other groups or classes of humans, etc.) and thus helps to set
the trap. Both economists and ecologists tend to fall into the trap of
assuming that individuals are optimizing and then interpreting all observed
behavior as optimal (since it is exhibited by optimizing individuals). By this
reasoning discounting the future must be optimal because humans do it and
they are optimizing individuals. The psychological evidence indicates, however, that humans have problems responding to reinforcements that are not
immediate (in time and space), and can be led into disastrous situations
because they discount too much.
Discounting future value by the rate of interest also provides an extremely
tight link between ecological destruction and macroeconomic policy. Any
exploited species whose natural rate of population growth is less than the
rate of interest is under threat of extinction, even in the absence of common
property problems. It is a bit far-fetched to imagine Paul Volker and the
FED worrying about the effect of U.S. interest rate policy on deforestation
in the Amazon, but that is simply evidence of the unwarranted isolation of
economics from ecology, because such links really do exist.
Non-monetized values and the partial quantification trap
There is a limit to what we can do with numbers, just as there is a limit to
what we can do without them. Not all values can be quantified in monetary
terms at the same level of precision. Comparing non-monetized values with
each other and with monetized values is difficult but obviously not impossible since we do it all the time. In an age of number crunchers, however,
there is a danger that the more precisely expressible values will dominate the
less precisely expressible values simply because their numerical character
makes them easier to fit into models. Against this 'unfair' advantage of
precise numbers, however, must be balanced an 'unfair' advantage of the
poorly-measurable. If something can be precisely measured it is hard to
exaggerate its magnitude. It is what it is. But imprecise values can be
exaggerated, and exposing the exaggeration is not always easy.
One approach is to try to quantify all values in a common metric, on the
grounds that any decision trade-off between the priced and the non-priced
implies some shadow price implicitly given to what was not priced. That
may be true, but it is the order of causation that is crucial. The fact that
after the fact such a decision implies some shadow price does not mean that
before the fact we have any means of calculating that price independently in
order to use it as the basis of the decision.
The only solution to the partial quantification trap is to recognize and
deal with the range of imprecision inherent in any decision. This means
looking at the full range of possible outcomes, given the level of precision of
our models and data, and making decisions in that context. It is seductive to
try to obtain a precise, decisive, answer by using as input to precise
mathematical models only that which we can measure precisely. But it is
extremely dangerous to do so. As Albert Einstein once said; " t h e laws of
mathematics, as far as they refer to reality, are not certain, and as far as they
are certain, do not refer to reality."
Integration vs. cross fertilization
Some writers aim at full integration of economics and ecology. Others,
more modestly, seek only cross fertilization by borrowing constructs from
one discipline and applying them in the other. In this volume several
strategies of integration are attempted. VAN DER PLOEG et al. summarize a
broader range of attempts at various forms of integration and cross fertilization (what they call "stretching") that have thus far been made. VERTINSKY uses the concepts of diversity, stability and resilience from ecology to
illuminate the functioning of the Japanese style of management and economic decision-making. Many ecologists have imported the economic model
of i n p u t - o u t p u t economics into ecology. Perhaps this particular borrowing
is really the repayment of an old debt that economics owes to the life
sciences, since the i n p u t - o u t p u t model derives from Quesney's 'tableau
economique' which was suggested to Quesney (a physician) by the analogy
of the circulation of blood in the body to the circulation of income among
social classes in the body politic.
Extending classical neoclassical, and marxist analysis
The papers that do aim at a new integrative synthesis take several
different starting points. GOODLAND and LEDE¢, and PEARCE, attempt to
expand the boundaries and concepts of neoclassical economics so as to
embrace the important economic development issues of sustainability and
carrying capacity, yet within an overall neoclassical framework of comparing
costs and benefits at the margin.
CHRISTENSEN offers the notion that the extension of classical economics
may offer greater possibilities of integrating ecology and economics than
does neoclassical economics, and casts modern energy analysis as a form of
classical revival. Similarly, KAUFMANN wonders if Marxist economics might
not offer the best starting point for the development of integration, which he
also sees as being exhibited in its early stages by modern energy analysts.
Systems ecology and energy analysis
The systems ecology approach exhibited by CLEVELAND and by
NORGAARD seeks to envelop economics in an overall ecological framework:
NORGAARD takes coevolution as the key concept, while CLEVELAND and
other energy analysts take energy flows as the dominant integrating principle.
Both disciplines have been cross-fertilized, and indeed to a degree integrated, by borrowing from a third discipline, thermodynamics. The laws of
thermodynamics set the basic conditions of usefulness of matter-energy,
whether for metabolism or production, and define the way in which both
economies and organisms live off the environment by "sucking low entropy
from it" as Erwin Schroedinger put it, and as was seen by Frederick Soddy
even earlier. Several of the papers incorporate this fundamental tenet in
various forms. LAITNER looks explicitly at the implications of considering
resource constraints (particularly energy) in constructing economic development strategies.
TOWARD A TRUE SYNTHESIS
To effect a true synthesis of economics and ecology is the second most
important task of our generation, next to avoiding nuclear war. Without
such an integration we will gradually despoil the capacity of the earth to
support life. Gradual despoilation is certainly preferable to destroying it all
at once in a nuclear war, but is still an unhappy prospect. The importance of
the topic is more than sufficient justification for this special issue. It would
be pleasant to report that the integration of economics and ecology has
reached its full perfection in this volume. The truth, however, it that we are
just a few steps beyond the beginning. We know this problem will increasingly attract the efforts of scientists and scholars in the future, and hope that
this collection may in some way encourage and facilitate that important
work.
REFERENCES
Costanza, R., 1987. Social traps and environment policy. BioScience,37: 407-412.
Cross, J.G. and Guyer, M.J., 1980. Social traps. University of Michigan Press, Ann Arbor,
MI.
Platt, J., 1973. Social traps. Am. Psychol., 28: 642-651.