Amity Shlaes and Matthew Denhart criticized the proposal by Senators Lee and Rubio to cut taxes; I wrote two posts in the Corner; and now they’re back to defend their criticisms. Sort of. They retreat from their two main criticisms. Those were that the Lee-Rubio plan left the top tax rate so high that it stopped them cold, and that it’s the senators’ desire for a bigger child credit that compels this high top tax rate. (“Hostage to the Child Credit” was their headline, which accurately captured the thrust of the article.)

In that original article, they noted that earlier Republicans, such as Mitt Romney and Steve Forbes, had sought lower rates. I pointed out, and they now concede, that the top tax rate has been lower than 35 in only 3 of the last 80 years. So much the worse for the last 80 years, they now say. Fair enough. Perhaps in complaining that the Lee-Rubio tax-cut proposal took their breath away with its high rates, they should have mentioned that their breath has been taken away for a few generations, and that the Reagan tax cut of 1981 would have elicited an even worse reaction (he only brought the top rate to 50 then). Reagan managed to get the top rate down to 28 percent in his second term, as they note. But the price for that achievement was much higher tax rates on investment than Shlaes, Denhart, or I would like to see.

I pointed out that Shlaes and Denhart were wrong about the effects of the child credit on tax rates in the Lee-Rubio proposal: If they refrained from enlarging the credit, the top tax rate could go down only an additional 3 points. (It would go from 40 to 32 instead of from 40 to 35.) They mention this fact and attempt no refutation. There goes the hostage.

A couple of odds and ends: 1) Shlaes and Denhart talk up the idea of expanding IRAs substantially. That’s a good idea that is compatible with expanding the child credit, but it’s an idea that would not do nearly as much for savings or for middle-class families as they suppose. And it would leave parents, especially the parents of several children, paying a disproportionate share of taxes. That they pay too large a share of the tax burden is the basic case for the child credit, which they never address. Instead they treat the next generation as a “special-interest group.”

2) They complain that Lee and Rubio “would even raise taxes on some people.” Note that in the last round they lauded the Romney and Forbes tax plans, which would also have raised taxes on some people. It is an unavoidable feature of any tax-reform plan that is not a huge tax cut. If you get rid of tax breaks for people who do their own composting, or whatever, some of them are going to pay more than they did before.

Like a lot of criticisms of the Lee-Rubio plan, these would be easier to judge in comparison to an alternative. I strongly suspect that an alternative that brought the top rate down into the 20s would either be a net tax increase on the middle class or require very large deficits, and in either case be much less likely to result in the enactment of any tax-rate reduction at all.