The theory of optimal taxation has often been criticized for being of little practical policy relevance, due to a lack of robust theoretical results. This paper argues that recent advances in optimal tax theory has made that theory easier to apply and may help to explain some current trends in...

This paper considers optimal linear tax structures that are differentiated according to group membership. Groups can be heterogeneous with respect to both preferences and abilities. Contrary to most arguments in favour of tax privileges for certain groups, e.g. gender-based taxation, it is shown...

The paper provides a new formulation of the Mirrlees-Seade theorem on the positivity of the optimal marginal income tax, under weaker assumptions and in a more general model. The formulation of the theorem is independent of whether the model involves finitely many types or a continuous type...

We characterize optimal policies in a multidimensional nonlinear taxation model with bunching. We develop an empirically relevant model with cognitive and manual skills, firm heterogeneity, and labor market sorting. The analysis of optimal policy is based on two main results. We first derive an...

In a recent article, I demonstrated that, under standard simplifying assumptions, it is possible to finance a public good in a manner such that a Pareto improvement results whenever the simple cost-benefit test is satisfied -- that is, without any adjustment for the "marginal cost of funds." In...

In a recent article, I demonstrated that, under standard simplifying assumptions, it is possible to finance a public good in a manner such that a Pareto improvement results whenever the simple cost-benefit test is satisfied -- that is, without any adjustment for the "marginal cost of funds." In...

The paper provides a new proof of the positivity of the optimal marginal income tax, in a more general model, under weaker assumptions. The analysis focusses on the (weakly) relaxed problem in which upward incentive constraints are replaced by a monotonicity condition on consumption. Without...