Questions about statistical claims in paper from recent Nobel prize winners; some general challenges in trying understand nonlinear patterns using quadratic regression

A colleague who specializes in the natural selection of bad science points us to this article from 2005, Competition and Innovation: An Inverted-U Relationship, by Philippe Aghion, Nick Bloom, Richard Blundell, Rachel Griffith, and Peter Howitt. But the above graph … Continue reading → …