We construct an equilibrium random matching model of the labour market, withendogenous market participation and a general matching technology that allows formarket size effects: the job-finding rate for workers and the incentives for participationchange with the level of unemployment. In...

This paper develops a formula for the optimal nonlinear income tax, the terms of which are familiar from the theory of linear income taxation. The development uses the idea of a perturbation of the optimal schedule and is based upon as assumption of differentiability. It is also shown that the...