@page_eco Noel (2003) concluded from Canadian data that cycles were more common in cities with lots of small independents and resulted in lower mark ups. That seems more intuitive to me than the elaborate collusion that other studies suggest. But it is an area ripe for further work.
@ProfWrightGMU @DanWall55 The economic logic and bottom up reasoning in the 2010 HMGs has also seen them relied on in antitrust proceedings around the world. This looks likely to be lost with the new guidelines reliance on US case law.