The FTC’s proposed HSR rule changes would have imposed considerable compliance costs, requiring firms to report labor data with little analytical value. Even workplace-safety violations were included — without evidence linking them to market power.

Defining relevant labor markets for antitrust is another challenge. Take the FTC’s Kroger/Albertsons case: it defined a market for “union grocery labor,” ignoring competition from non-union jobs and other industries. This narrow definition doesn’t reflect reality.

Beyond these few studies, it's not even clear that labor-market concentration is a significant concern. Labor-market concentration has actually declined over time, as shown by @kevinrinz.bsky.social and others. Claims of pervasive employer dominance are overstated.

The studies cited by Posner — which do indeed constitute the bulk of the direct evidence — show *context-specific* effects, not broad evidence of systemic labor-market harm from mergers. The empirical base linking mergers to wage suppression is remarkably thin.

The push for aggressive labor antitrust enforcement is growing, but is it backed by solid evidence? At Truth on the Market, @briancalbrecht.bsky.social and I argue that the case for expanded labor antitrust is (at least so far) weaker than proponents claim. 🧵

The speaker lineup for our Jan. 17 "Substance Over Slogans" antitrust event in Paris is phenomenal, IMHO. Registration is open and spots are filling up!

More info/registration here: laweconcenter.org/events/subs...

Wow! Huge congratulations to ICLE board member, ICLE academic affiliate, and UChicago Law prof., Todd Henderson, on his victory over an incredibly tough field of competitors in the George Mason LEC Manne Madness Tournament!!