We study optimal income taxation when labor supply reacts along the intensive and extensive margins. Individuals are heterogeneous across two unobserved dimensions: their skill and disutility of participation. We develop a new method to analytically derive conditions under which optimal marginal...

Using the Mirrlees optimal income tax model under maximin, we derive fairly mild conditions for a decreasing marginal tax rate throughout the skill distribution with no bunching, a strictly concave tax function in income and a single-peaked average tax schedule. Assuming additive preferences and...