Weekly first-time claims for unemployment insurance, averaged over four weeks to remove holiday noise. Claims are the earliest published labour-market series and turn up before the unemployment rate does.

Threshold source: worldstat.us construction: sustained 15 % rises above the trailing low preceded every recession since 1970 without a false signal outside 2020 supply shocks. How thresholds are chosen

Seasonal adjustment around holidays and hurricanes produces spikes that reverse. Coverage of gig and self-employed workers is nil, so structural changes in the workforce lower the level over time.