Income Tax and National Insurance are now sufficiently similar that merging them appears to be a plausible option, yet still sufficiently different that integration raises significant difficulties. This paper surveys the potential benefits of integration – increased transparency and reduced...

This paper computes the optimal progressivity of the income tax code in a dynamic general equilibrium model with household heterogeneity in which uninsurable labor productivity risk gives rise to a nontrivial income and wealth distribution. A progressive tax system serves as a partial substitute...