rewrite this In The Great Reversal: How America Gave Up on Free Markets, Thomas Philippon argues that the United States has seen a marked decline in market competitiveness because of increased market concentration, as indicated by the Herfindahl-Hirschman Index (HHI). He suggests that this concentration dampens innovation and is detrimental to consumers. Contrary to Philippon's argument, our critique highlights that his reliance on the HHI to gauge market health greatly simplifies the intricate interplay between market concentration, competitiveness, and innovation. We advocate for a broader approach that includes a range of factors beyond mere concentration metrics to reflect market dynamics accurately. Additionally, we present evidence that, in contrast to Philippon's claim, higher market concentration in specific sectors may accompany an increase in innovation, thus questioning the book's broader implications regarding the competitiveness of American markets relative to Europe. This argument prompts a reevaluation of the effects of market concentration on innovation and competitiveness