This article explores subjects in optimal income taxation characterized by recent research interest, practical importance in light of concerns about inequality, potential for misunderstanding, and prospects for advancement. Throughout, the analysis highlights paths for further investigation....

The philanthropic sector is highly consequential, particularly in the United States, and the most important policies directed toward this sector are tax policies. Yet most economic analysis of the optimal tax treatment of charitable giving is ad hoc, treating it as a subject unto itself. This...

We consider optimal joint nonlinear earnings taxation of couples. We use multi-dimensional mechanism design techniques to study this problem and show that the first-order approach - that restricts attention to only local incentive constraints - is valid for a broad set of primitives. Optimal...

We use detailed data from Indonesian cities to study how variation in density within urban areas affects social capital. For identification, we instrument density with soil characteristics, and control for community averages of observed characteristics. Under plausible assumptions, these...

We study the volunteer's dilemma in environments with heterogeneous preferences and private information. We characterize the efficiency properties of equilibrium, which is a departure from all the previous literature that focuses only on the probability of group success. While the probability of...

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...

When is a wealth tax preferable to a capital income tax? When is the opposite true? More generally, can capital taxation be structured to improve productivity, incentivize innovation, and ultimately increase welfare? We study these questions theoretically in an infinite-horizon model with...

We provide a unified analysis of taxation and taxpayer education when individuals have an incomplete understanding of a complex tax system. The analysis is independent of whether income is earned legitimately, or by avoiding or evading taxes. In this sense, learning about tax minimization...

Products with negative externalities are often subject to regulations that limit competition. The single-product case may suggest that it is irrelevant for aggregate welfare whether output is restricted via corrective taxes or limiting competition. However, when products are differentiated...

Tax harmonization entails a uniform rate that may not suit all governments. Harmonization can advance collective governmental objectives only if the standard deviation of tax rates is less than the average downward effect of tax competition on rates. Since an efficient harmonized tax rate undoes...