A Never-decisive and Anonymous Criterion for Optimal Growth Models

We address in this paper the question of the existence of a Social Welfare Function that would be sustainable and would allow to obtain solutions to optimal growth models. We define sustainabil- ity by two new axioms called Never-decisiveness of the present and Never-decisiveness of the future. We first show that a SWF which has Never-decisiveness properties cannot be defined on a ball of l+ . We must (i) restrict to the set of utility streams for which the value of the SWF is finite and (i) introduce additional assumptions in order to obtain the Never-decisiveness properties. Our main result in this pa- per is therefore to show that the undiscounted utilitarian criterion is an anonymous and never-decisive criterion for optimal growth models. We consider the set of utilities of consumptions which are generated by a specific technology, namely a technology with decreasing returns for high levels of capital and restrict ourselves to good programmes, i.e. any programme for which intertemporal utility is well defined.