Avik Roy succinctly lays out several arguments against tax relief for parents. Succinctly, but unconvincingly. I’ll go through them one by one (although I will go very slightly out of order, and not use his numbering).

1) It’s supposedly an “effort at social engineering” designed “to encourage more Americans to make babies.” Roy produces no quotes from the sponsors of the legislation, Senators Lee and Rubio, stating this goal; nor, I suspect, will he find any from previous supporters of the child credit stretching back to the Contract with America. Supporters of the credit have generally made one or both of two arguments: They want to help parents; and tax relief for parents is justified because parents pay a disproportionate share of the tax burden. Roy does not rebut this argument, or even mention it.

2) It might not lead to more babies being born. That would be a fine counterargument if his premise in 1 had been correct. It’s irrelevant to the actual arguments proponents of the credit have been making.

3) It might lead to more kids being born out of wedlock. I’m not sure why we should be simultaneously skeptical that any more kids will be born and inclined to think that if any are, they will be born out of wedlock. If anything, I think we should expect a disproportionate response by married parents, who are more likely to have tax liabilities for the child credit to offset.

4) We “have a democratic imbalance” because two-fifths of Americans pay no income tax, and the child credit would make this imbalance worse. Here Roy’s succinctness comes at the expense of actually spelling out what his concern is. I will therefore respond to the most common form of this argument, which is that people who don’t pay taxes will come to favor big government since it will be free to them. In response I’d note a) that nobody paid direct taxes for the first half of the existence of the United States, and we managed to have a much smaller government, b) that there’s no actual evidence that people who don’t pay taxes become liberals in response; c) that there’s no evidence that the parents who have come off the income-tax rolls because of the child credit have changed their political behavior in this way; and d) that parents would come off the tax rolls only temporarily, and are likely to be a relatively future-oriented group of voters.

5) The Lee-Rubio plan will make the tax code more progressive. I have no idea whether this is true—the plan’s liberal critics certainly dispute the point—and Roy provides no metric for evaluating it. But if a set of changes to the tax code make the tax code more pro-growth and less burdensome for families, I think it would be perverse to reject those changes because progressivity increased.

6) It accelerates the bankruptcy of Social Security and Medicare. Here Roy buries a reasonable point beneath the government’s phony accounting: Lee-Rubio causes revenue to fall a lot, and the senators have not specified spending cuts to make up for it. (To the extent the credit enables people to have additional children, however, this effect would help the fiscal health of the entitlements.)

7) The child-credit portion of the Lee-Rubio plan contributes nothing to economic growth. This criticism seems myopic, since the plan as a whole does increase economic growth, and the plan would be much less politically viable if it substituted even lower tax rates for the expanded child credit, as Roy suggests in conclusion.

But I’d like to end on a note where I’m pretty sure Roy and I would agree, which is that I look forward to seeing what Rubio’s presidential rivals come up with—something that will help put the advantages and disadvantages of his plan in perspective.