There has been much academic debate on the exact meaning that should be ascribed to the term “sustainability.” Tietenberg suggests that sustainability means “future generations remain at least as well off as current generations” (Tietenberg 1984, p. 33). In more formal language, the above formulation implies that sustainability means “non-declining utility.” Repetto states, in the same vein, that “current decisions should not impair the prospects for maintaining or improving future living standards” (Repetto 1985, p. 16). The World Commission on Environment and Development suggests, in the same vein, that sustainable development “meets the needs of the present without compromising the ability of future generations to meet their own needs” (WCED 1987). Pearce et al. (1989) and Hoagland and Stavins (1992) have collected a number of other definitions in the literature.

Apart from being unsatisfactory from the standpoint of reflecting non-economic elements of sustainability, these definitions share another common feature: they are unquantifiable and, absent quantitative measures, unverifiable. Some are sufficiently vague as to permit contradictory conclusions as to whether or not the conditions for sustainability are being met in any particular case. This permits – perhaps, indeed, encourages – perverse interpretations of sustainability to justify continued business-as-usual by business, governments and even the World Bank.