We derive a sufficient statistics optimal tax formula in a general model that incorporates unemployment and endogenous wages, to study the shape of the tax and transfer system at the bottom of the distribution. The sufficient statistics are the macro employment response to taxation and the micro...

We solve a large class of multidimensional adverse selection problems with one observed action, to derive the nonlinear optimal income tax schedule when individuals differ along multiple unobserved characteristics. Based on a perturbation of the optimal allocation, our method allows individuals...