Taxation and the Superrich
梳理了现代最优累进税文献，指出超级富豪的收入性质与其他群体不同，强调税率弹性并非结构参数，应同时关注税基尤其是资本利得。
This article addresses the modern optimal tax progressivity literature, which clarifies the key role of the behavioral response to taxation and accounts for the incomes of the superrich being qualitatively different from others. Some of the superrich may be “superstars” for whom small differences in talent are magnified into much larger earnings differences, while others may work in winner-take-all markets, such that their effort to climb the ladder of success reduces the returns to others. We stress that pivotal tax-rate elasticities are not structural parameters and will be smaller the broader and less plastic is the tax base and the more effective is the enforcement of tax evasion. For this reason, normative analysis of tax rates should be accompanied by attention to the tax base, with a special focus on capital gains, which comprise a large fraction of the taxable income of the superrich.