An annual wealth tax, a mark-to-market income tax, and a retrospective capital gains tax are three approaches to capital taxation that yield roughly equivalent outcomes under certain conditions. The three approaches differ starkly, however, in their exposure to uncertainty of various types. This essay seeks to highlight the effect of uncertainty on the implementation and operation of alternative capital taxation regimes. An annual wealth tax is highly vulnerable to valuation uncertainty and constitutional uncertainty, but less so to political uncertainty. A retrospective capital gains tax, by contrast, minimizes valuation uncertainty and effectively eliminates constitutional uncertainty but remains highly exposed to political uncertainty. A mark-to-market regime falls somewhere between the two extremes on dimensions of political and constitutional uncertainty but shares in a wealth tax’s exposure to valuation uncertainty. Ultimately, the choice among alternative capital taxation regimes reflects a trade-off among uncertainties of different varieties.

中文翻译：

---

不确定世界中的财富征税

年度财富税，按市值计价的所得税和追溯性资本利得税是三种资本税的方法，可以在某些条件下产生大致相同的结果。但是，这三种方法在暴露于各种类型的不确定性方面截然不同。本文旨在强调不确定性对替代性资本税制实施和运作的影响。年度财富税极易受到估值不确定性和宪法不确定性的影响，而对政治不确定性的影响则较小。相比之下，追溯性资本利得税可以最大程度地减少估值不确定性，并有效消除宪法上的不确定性，但仍然极易受到政治不确定性的影响。按市值计价的制度在政治和宪法不确定性方面处于两个极端之间，但在财产税中存在估值不确定性。最终，替代性资本税制中的选择反映了不同品种不确定性之间的权衡。