This paper proposes measures to quantify the effective level and the effective progressivity of taxation in a fiscally decentralized country taking income sorting into account. Using data on the universe of Swiss taxpayers, we find that rich households effectively face significantly lower...

We derive a general optimal income tax formula when individuals respond along both the intensive and extensive margins and when income effects can prevail. Individuals are heterogeneous across two dimensions: their skill and their disutility of participation. Preferences over consumption and...

This paper characterizes optimal income taxation when individuals respond along both the intensive and extensive margins. Individuals are heterogeneous across two dimensions: specifically, their skill and disutility of participation. Preferences over consumption and work effort can differ with...