We propose a social welfare function to evaluate a profile of income streams and compare the welfare gain of the actual profile relative to the income profile where the individual receives his first period income in each period. We derive necessary and sufficient conditions for the welfare...

This paper assumes the standard optimal income tax model of Mirrlees (Review of Economic Studies, 1971). It gives fairly mild conditions under which the optimal nonlinear labor income tax profile derived under maximin has higher marginal tax rates than the ones derived with welfarist criteria...