Specialized theoretical and empirical research should in principle be embedded in a unified framework that identifies the relevant interactions among different phenomena, enables an appropriate matching of policy instruments to objectives, and grounds normative analysis in individuals' utilities...

There is increasing empirical evidence that people systematically differ in their rates of return on capital. We derive optimal non-linear taxes on labor and capital income in the presence of such return heterogeneity. We allow for two distinct reasons why returns are heterogeneous: because...

This paper characterises optimal taxation when rates of return are affected by effort, ability, and financial advice. When the government observes wealth and capital income, the optimal marginal tax rate on capital income is positive, whereas the rate on wealth is negative in the baseline model....