This paper analyzes the optimal income tax treatment of couples. Each couple is modelled as a single rational economic agent supplying labor along two dimensions: primary and secondary earnings. We consider fully general joint income tax systems. Separate taxation is never optimal if social...

This paper provides estimates of federal tax rates by income groups in the United States since 1960, with special emphasis on very top income groups. We include individual and corporate income taxes, payroll taxes, and estate and gift taxes. The progressivity of the U.S. federal tax system at...

This paper presents new findings on global inequality dynamics from the World Wealth and Income Database (WID.world), with particular emphasis on the contrast between the trends observed in the United States, China, France, and the United Kingdom. We observe rising top income and wealth shares...