William J. Hartnett*
ustainable development" has become a rallying cry around the world. It has rich conceptual roots, but has given rise to different interpretations which have been subjected to a variety of critiques. This article recalls the conceptual evolution of sustainable development and the worldwide consensus in support of it.
Origins of the Concept of Sustainable Development
The classic definition is that "[s]ustainable development is development that meets the needs of the present without compromising the ability of future generations to meet their own needs."1 In particular, the elimination of poverty has been emphasized as the first priority of sustainability.2 This aspiration struck a resonant chord around the world and helped mobilize an evolving global consensus for sustainable development.
The next stage in the conceptual development of sustainable development was to characterize it as an ongoing increase in each component of social welfare, including such items as real income, health, education and access to resources.3 Alternatively, sustainable development has been defined as non-declining utility of a representative member of society.4
Current Economic Paradigm of Capital Maintenance
According to the current economic paradigm, sustainable development should be interpreted as the maintenance of capital. This policy prescription is subdivided into four variations of increasing strictness.5
Very weak sustainability, or "Solow sustainability," requires only that the total capital base be maintained. This is accomplished by keeping consumption below "Hicksian income," defined as the maximum level of consumption which leaves society as well off at the end of a period as at the beginning.6 In other words, the depletion of natural resources must be taken into account in the valuation of economic activity.7
Weak sustainability also requires that total capital be maintained, but subject to the further constraint that critical natural capital be conserved. For example, if water resources and species diversity are necessary for ecosystem stability, they cannot be sacrificed at the altar of economic growth.
Strong sustainability claims that there is no true substitute for natural capital, because it enhances human welfare in many different ways and its degradation can be effectively irreversible. Strong sustainability calls for the maintenance of total capital, subject to a further constraint that aggregate natural capital be conserved.
Very strong sustainability calls for a steady state world system, with zero economic growth and zero growth in human population. Resource-independent "development" would be allowed, but resource-dependent "growth" would be precluded. This interpretation calls for the separate maintenance of each component of natural capital, and is actually a systems rather than economic concept.
Some Critiques of Current Definition
The classic "needs" based definition can be questioned as vague. The non-declining utility approach cannot be operationalized. A very strict sustainability steady state appears infeasible, at least in the near term.
As for the social welfare and capital maintenance approaches, if a category is specially designated so that it cannot be allowed to decrease at all, then policy options which even negligibly impair that category in exchange for even arbitrarily great improvement in other forms of welfare are unrealistically excluded. For example, with the social welfare approach, if food production and housing are the two components of social welfare, then tripling total food production at the expense of even a single hut would violate the sustainability constraint.
Political Progress in Support of Sustainable Development
Despite such critiques, these attempts to define sustainable development have nonetheless engendered world-wide political support for it. In 1972, the United Nations Conference on the Human Environment convened with representatives from 113 countries. The resulting Stockholm Declaration, adopted by proclamation, heralded as its first Principle:
"Man has the fundamental right to freedom, equality and adequate conditions of life, in an environment of a quality that permits a life of dignity and well-being, and he bears a solemn responsibility to protect and improve the environment for present and future generations . . ."
Twenty years later, representatives from 178 countries gathered in Rio de Janeiro for the United Nations Conference on Environment and Development. The concept of sustainable development permeates the resulting consensus expressed in the Rio Declaration. As just one example, Principle 1 declares:
"Human beings are at the centre of concerns for sustainable development. They are entitled to a healthy and productive life in harmony with nature."
The consensus of these and other international convocations has been reinforced by numerous government policy makers, academics, writers, business executives, and "ordinary people" around the world.
Conclusion
Sustainable development continues to conceptually evolve. Worldwide support for it continues to grow. Government policy makers have a corresponding responsibility to develop strategies to achieve sustainable development. By adopting such strategies, a country's leaders can serve their citizenry, and earn the gratitude of their descendants as well.
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William J. Hartnett is a policy advisor in privatization and sustainable development.
References
1 The World Commission on the Environment and Development, Our Common Future (1987).
2 Prime Minister Gro Harlem Brundtland, Sir Peter Scott Lecture, Bristol (October 8, 1986). Edward Barbier, The Concept of Sustainable Economic Development, 14(2) Environmental Conservation 101-10 (1987). Mustafa Tolba, Sustainable Development—Constraints and Opportunity (1987).
3 David Pearce, Edward Barbier, Anil Amarkandya, Sustainable Development and Cost-Benefit Analysis, London Environmental Economics Centre Paper 88-01 (1988).
4 John Pezzey, Economic Analysis of Sustainable Growth and Sustainable Development, World Bank Environment Department Working Paper No. 15 (May, 1989).
5 This conceptual taxonomy is found in R. K. Turner, "Sustainability: Principles and Practice," in R. K. Turner (ed.) Sustainable Environmental Economics and Management: Principles and Practice, 9-14 (1993).
6 Herman E. Daly, John B. Cobb, Jr., For the Common Good: Redirecting the Economy Toward Community, the Environment, and a Sustainable Future 70-71 (1989), quoting Sir John Hicks, Value and Capital 172 (1948).
7 This version of sustainable development is called "Solow sustainability" after the Nobel laureate MIT economist Robert Solow, who has expressed his views in Sustainability: An Economist's Perspective (Woods Hole Oceanographic Institute lecture of June 14, 1991), and An Almost Practical Step Toward Sustainability (Resources for the Future lecture of October 8, 1992).