Responsibility, inequality, efficiency, and equity in four sustainability paradigms: insights for the global environment from a cross-development analytical model

This paper develops a theoretical framework to assess the feasibility of global environmental sustainability solutions based on one or more value changes. The framework represents four sustainability paradigms (weak sustainability WS, a-growth AG, de-growth DG, strong sustainability SS) and five value changes (i.e. a sense of responsibility for nature, future generations, or the current generation in developing countries; aversion to inequality for the current generation or future generations). It defines solutions in terms of consumption, environment use, and welfare for representative individuals in both developed (OECD) and developing (non-OECD) countries. Solutions are characterised by efficiency (i.e. Pareto and Kaldor–Hicks) with respect to welfare and by intra- and inter-generational equality for consumption, environment use, and welfare, by confirming internal consistency and consistency with alternative equity approaches for utilitarianism (i.e. Harsanyi), egalitarianism (i.e. Arneson for welfare; Dworkin for consumption or environment use; Sen for consumption and environment use), and contractarianism (i.e. Rawls). Theoretical and operational insights are described for alternative sustainability paradigms and equity approaches. In terms of feasibility based on improved technology, decreased population, and modified consumption, the ordering is responsibility for future generations > responsibility for the current generation in developing countries > aversion to inequality for the current generation > aversion to inequality for future generations and AG > SS > DG > WS: responsibility for nature is unfeasible. In terms of internal consistency, responsibility for future generations > responsibility for the current generation in developing countries = aversion to inequality for the current generation = aversion to inequality for future generations and SS > AG > DG; WS is internally inconsistent. In terms of consistency with an equity approach, responsibility for future generations > responsibility for the current generation in developing countries = aversion to inequality for future generations > aversion to inequality for the current generation and SS > AG > DG > WS.