Paweł Doligalski

We extend the theory of the optimal redistributive taxation to economies with an informal labor market. The optimal tax formula contains two new terms capturing reported income responses of informal workers on an intensive and an extensive margin. Both terms decrease the optimal tax rates. We quantitatively show that this reduction can be substantial, exceeding 30 percentage points, and we document a large welfare gain of up to 6.4% of consumption from following our tax formula rather than the standard formula. We also provide a novel decomposition of the welfare impact of the shadow economy into labor efficiency and redistribution components. In the quantitative model estimated with Colombian data the shadow economy benefits efficiency at the expense of redistribution. As a result, conditional on the optimal tax policy, the presence of the informal sector does not substantially affect social welfare unless social preferences for redistribution are strong.

New Dynamic Public Finance describes the optimal income tax in the economy without private insurance opportunities. I extend this framework by introducing permanent employment contracts which facilitate insurance provision within firms. The optimal tax system becomes remarkably simple, as the government outsources most of the insurance provision to employers and focuses mainly on redistribution. When the government wants to redistribute to the poor, a dual labor market could be optimal. Less productive workers are hired on a fixed-term basis and are partially insured by the government, while the more productive ones enjoy the full insurance provided by the permanent employment. Such arrangement discourages the tax avoidance of the productive workers and hence allows the government to tax them more. I provide empirical evidence consistent with the theory and characterize the constrained efficient allocations for Italy.

When does paying a strictly positive compensation in every state of the world improve incentives to exert effort? I show that in the typical model of moral hazard it happens only when the effort is a strict complement to consumption. If the cost of effort is monetary, a positive minimal compensation strengthens incentives only when the agent is prudent and always does so when the marginal utility of consumption is unbounded at zero consumption. I suggest applications of these results in the personal income taxation.