American Economic Review Vol. 116 No. 7 2026
The Effect of High-Tech Clusters on the Productivity of Top Inventors: Comment
Abstract
Moretti (2021) reports a positive elasticity between technology cluster size and patenting, and uses an event study and instrumental variables regressions to justify a causal interpretation. The event study does not use the variation generated by inventors moving across cities, and the instrument is constructed incorrectly due to a coding error. I run a corrected event study and fix the coding error, and find null effects. The reported elasticity may not be causal.
- DOI
- 10.1257/aer.20231415
- Volume
- 116
- Issue
- 7
- Pages
- 2754-2763
- Language
- en
- Sources
- openalex crossref