A loyal MR reader asks:
What are your thoughts on the new dynamic optimal public finance policy models being built and simulated? Will they yield any new insights applicable for the real world, or are they a fad?
Real insights maybe, real measurements for sure. I take this paper by Mankiw to be a paradigmatic example. Through this body of literature we learn, or confirm our previous intuitions, that:
1. Cutting U.S. income tax rates is not, in general, self-financing. We also get a rough idea of how much revenue we can make up in the long run.
2. Many forms of corporate and capital income taxation are, in the long or even medium run, inefficient.
3. Ideally we should move to a consumption tax. (NB: Moving outside the models, I am scared that this kind of tax reform will just turn into another tax increase. We’ll add a VAT to income taxation rather than shift to the VAT. Yikes.)
These results are the bread and butter of applied public finance. You can complain all you want about the assumptions, the artificiality, and the use of intuition to throw out unacceptable calibrations, but at the end of the day there is not a better way to do the work.
A fad, perhaps, but there is nothing wrong with that. The Beatles were a fad too.
By the way, here is an interesting paper on a different frontier in public finance, namely field experiments.
#10 in a series of 50.