Toman, Michael A. 1992. "The Difficulty in Defining Sustainability." Resources 106 (Winter): 3-6.

Thesis:

Toman argues that ecologists and economists view sustainability in very different ways. Conceptually, there are three key reasons for this disagreement: intergenerational fairness, the substitutability of natural and other resources, and the carrying capacity of natural ecosystems. He introduces the concept of the "safe minimum standard" which he contends may be the mechanism to connect these two perspectives.

Summary:

Intergenerational fairness in economics involves "assigning benefits and costs according to some representative set of individual preferences, and discounting costs and benefits accruing to future generations just as future receipts and burdens experienced by members of the current generation are discounted" (p. 4). Ecologists have ciriticized this view in several ways. For one, they are ciritical of the economist's assumption that a "representative set" of individual preferences is justly representative of all or even most individual preferences. Additionally, deep ecologists take issue with the practice of placing human values at the center of the sustainability debate.

Resource substitutability, in an economist's point of view, claims that natural capital can be substituted with human capital. Ecologists, on the other hand, tend to view natural capital and ecosystem health as inherently valuable and so no practical substitutions exist.

Ecologists tend to see carrying capacity as limiting and so assume that human impact must be monitored to prevent carrying capacity overshoot. Economists, however, see carrying capacity as dynamic and so assume that resource substitution and technological innovation can adequately compensate for its fluctuations.

The safe minimum standard: Toman views this standard as a "rationale for some form of intergenerational contractit posits a socially determined dividing line between moral imperatives to preserve and enhance natural resource systems and the free play of resource tradeoffs" (p. 5). As a "thought experiment," it would require the current generation to determine a maximum threshold of cost and irreversibility and then restrict it from surpassing that threshold.

Toman concludes with a call for interdisciplinary research to refine the concept of sustainability. Economists need to incorporate the work of ecologists into their value analyses while ecologists need to recognize that "human behavior and social decision processes are complex, just as ecological processes are" (p. 6).

Keywords: safe minimum standard