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: the four-week average 15 % above its low of the past year. How thresholds are chosen
The rule fires outside recessions: in 2023 the average rose more than 30 % above its low with no recession following, and the hurricanes of 2005 and 2012 produced spikes that reversed within weeks. Coverage of gig and self-employed workers is nil, so structural changes in the workforce lower the level over time.