Megan McArdle Wednesday:
Chait, and others writing in this vein, refute the strongest claims of the supply-side movement: that tax cuts produce astonishing growth, or that cutting taxes can increase tax revenue. Then they imply that they have thereby refuted all the economic claims in favor of tax cuts, which they haven’t, not even close. … it’s not some sort of weird, uniquely awful Republican behaviour to sell your policies using dubious economic claims. … Politicians often assemble policies for a variety of reasons, and then sell them using the least plausible, but most appealing, rationale.
Any social worker, for example, will tell you that a core of their clients have no reasonable chance of getting off support. … But almost no social worker ever says, "We need welfare benefits because these people are too screwed up to hold a job", because Americans do not care to give money to people whom they perceive as not trying. Whether this is appalling dishonesty, or merely putting your best foot forward, depends much on how you feel about the underlying program.
If there were no relation between the quality of a policy conclusion and of the public arguments offered in its favor, then there would be simply no point in considering public arguments when evaluating a policy. Yet Megan spends most of her time critiquing public arguments offered for various policies.
So I think Megan must admit that the weakness of some arguments for tax cuts was in fact a bad sign about the wisdom of those cuts. Her point, I think, is that it wasn’t an overwhelming bad sign; Megan sees other good signs that could outweigh this bad sign.