Since around 1980, average tax rates of the top 1% of American earners have fallen as their incomes have risen.

自大约1980年以来，美国1%的富人阶层的收入增多了，但平均税率却降低了。

That gap explains why Mr Buffett, most of whose income comes from capital gains and dividends, has a lower average tax rate than his secretary.

这个差距显示了收入多为股息和资本收益的巴菲特先生的平均税率比他秘书低的原因。

It is also needlessly costly, riddled with quirks of the sort that allow Warren Buffett, an American billionaire, and the Republican presidential contender, Mitt Romney, to pay a lower average tax rate than many poorer households.

也不必说它的成本高昂了，有很多奇怪的制度设计使得美国亿万富翁巴菲特、共和党总统竞争者罗姆尼比许多贫困家庭支付的税率还要低。