The goal of this paper is to provide a definition of the concept of sustainability with the level of rigor and clarity of neoclassical theory, based on two axioms that ensure equal treatment of the present and the future introduced by the author. We discuss applications to markets, business...

New physical constraints emerged in the 20th century and are changing the decision criteria used until now. Two optimisation problems are equivalent: (1) maximising discounted utility with a long-run survival constraint and (2) maximising a new type of utility that treats the present and future...