The Lombard Review
Economy

The recession rule that's flashing amber

Unemployment rise triggers recession rule

Workers on a construction site
Workers on a construction sitePhoto: Boudoirphotographyguide / Wikimedia Commons, CC BY 4.0

Macroeconomic forecasting is littered with flawed empirical heuristics, but the Sahm Rule has earned a near-sacred reputation among monetary economists. Developed by Claudia Sahm, the rule states that a recession is underway whenever the three-month moving average of the national unemployment rate rises by 0.5 percentage points above its twelve-month low. Following the October jobs report, the Sahm metric reached 0.33 percentage points, flashing an unmistakable amber warning.

Market data screens at the Frankfurt Stock Exchange
Market data screens at the Frankfurt Stock ExchangePhoto: Ank Kumar / Wikimedia Commons, CC BY-SA 4.0

The Sahm Threshold

Non-farm payroll growth decelerated to 150,000, and the unemployment rate ticked up to 3.9 per cent. Historically, once the unemployment rate begins to rise, momentum becomes self-reinforcing as corporate retrenchment and household caution feed on each other. If the Sahm Rule triggers, it will suggest that the Federal Reserve's hyper-tightening has finally punctured the domestic business cycle.

The Manhattan skyline from Upper New York Bay
The Manhattan skyline from Upper New York BayPhoto: Jakub Hałun / Wikimedia Commons, CC BY 4.0

The Sahm Rule’s amber signal is a stark reminder to monetary policymakers that labour market deteriorations are notoriously non-linear once momentum begins to turn.