We consider optimal non-linear income tax problems when the social welfare function only depends on ranks as in Yaari (1987) and weights agree with the Lorenz quasi-ordering. Gini, S-Gini, and a class putting more emphasis on inequality in the upper part of the distribution belong to this set....

This article explores the use of workfare as part of an optimal tax mix when labor supply responses are along the extensive margin. Particular attention is paid to the interaction between workfare and an earned income tax credit, two policies that are designed to provide additional incentives...

We solve the non-linear income tax program for a rank-dependent social welfare function à la Yaari, expressing the trade-off between size and inequality using the Gini or related families of positional indices. The key idea is that when agents optimize and absent bunching, ranks in the actual...