Intergenerational equity, efficiency, and constructibility

Overtaking criteria and Chichilnisky criteria take the short and the very long run into account and are able to resolve intergenerational con- icts. Unfortunately, overtaking criteria are highly incomplete. In order to decrease this incompleteness, stronger anonymity (or equity) axioms were de- veloped. I show that a maximal anonymity axiom compatible with Pareto is a non-constructible object; its existence relies on the Axiom of Choice. The Chichilnisky criterion is based upon two axioms: non dictatorship of the present and non dictatorship of the future. Here, the very long run is captured by a nitely additive measure. Such a measure, however, is a non-constructible ob- ject and has therefore no explicit description.