Atkinson and Stiglitz show that with weakly separability, differential commodity taxes are unnecessary given an optimal nonlinear income tax. Deaton showed that with an optimal linear progressive income tax, commodity taxes are superfluous under weakly separable and linear Engel curves. Using...

We study political competition in an environment in which voters have private information about their preferences. Our framework covers models of income taxation, public-goods provision or publicly provided private goods. Politicians are vote-share-maximizers. They can propose any policy that is...