A general principle for an efficient tax system is to collect a given amount of revenue (corresponding in the long run to the government’s spending) in a way that causes as little distortion as possible to the overall economy. Usually, this principle means that marginal tax rates should be similar at different levels of labor income, for various types of consumption, for outlays today versus tomorrow, and so on.
有效税收制度的一个一般原则是以对总体经济扭曲程度尽可能小的方式征收给定数量（对应政府长期支出水平）的税额。通常，这一原则意味着不同水平劳动所得、不同类型消费以及不同征收时间（现在或将来）的边际税率应该相似。