Michael Wiebe writes:

My [Wiebe’s] replication of Moretti (2021) is now accepted as a comment at American Economic Review. Here’s the pdf. I show that the event study uses the wrong model, and the instrumental variable has a coding error. Fixing both issues leads to null results, so the positive correlation between cluster size and patenting may not be causal. I also document eight other issues in the appendix.

We mentioned this one a couple years ago. It’s good to hear that the criticism was published at the same journal as the original article. That almost never seems to happen! Credit to the AER for not being defensive. It’s inevitable that a journal that publishes a lot of papers will publish some with fatal errors; the AER just seems to be one of the few journals that can accept the implications of that.

I expect it took a lot of persistence on Wiebe’s part to get his comment through the review process; I usually lose patience with that sort of thing! For example, I don’t know where this one will ever get published.