Unpacking Progressivity is Ms. Shlaes article at NationalReview.com. It's actually a review of a book advocating higher taxes on the rich, but what makes the article worth reading is her summation of "progressivity," a word not fully understood by most.
She notes that progressivity was first introduced in the U.S. in 1913 with the income tax. Then this:
Over the hundred years intervening, studies have shown that generally people do think that the greater the wealth, the more dollars wealthy people should pay in tax, proportionally. But that is not a progressive rate structure. That is a flat tax. A progressive tax increases rates as you earn more, disproportionally. ...
Politicians, and the economists behind them, simply played off citizens’ ignorance. The simple early code of 1913 became complex and, yes, more onerous.
The real question should be why Americans allow themselves to be intimidated, especially when it comes to progressivity.
She offers two answers. One is that people don't want to admit that they don't understand, so, "like the Enron audit committee, they simply nod and go along." The other is that they don't want to appear unfair. Progressives take advantage of this.
Ms. Shlaes, with her uncomplicated explanation, is trying to help people overcome this ignorance.