Every recession indicator has a trade-off between speed and accuracy. The Sahm Rule sits in an unusually good spot on that spectrum, triggering early enough to be useful while maintaining a near-perfect historical record.
The mechanics are straightforward. Take the three-month moving average of the national unemployment rate. Compare it to the lowest three-month moving average from the prior twelve months. If the difference hits 0.5 percentage points or more, the rule triggers. Since 1970, every recession has seen this trigger, and there have been almost no false positives.
What makes it interesting for traders is the timing. The Sahm Rule has historically triggered near the beginning of recessions, not the middle or end. By the time traditional indicators like two consecutive quarters of negative GDP growth confirm a recession, markets have usually already repriced significantly. The Sahm Rule tends to flash earlier.
In 2024, the indicator triggered briefly, which led to intense debate about whether its track record would hold. The unemployment rate rose for reasons partially related to labor force expansion rather than pure job losses, which was a different dynamic than prior triggers. This highlights an important caveat: the rule was designed for a specific mechanism (rising unemployment driven by layoffs), and when unemployment rises for other reasons, the signal can be less clear.
For market participants, the practical application goes beyond binary recession calls. The Sahm Rule reading can be tracked continuously as a gauge of labor market deterioration speed. Even below the 0.5 threshold, a rising reading suggests the labor market is softening, which has implications for Fed policy expectations and risk asset pricing.
Combining the Sahm Rule with other recession indicators creates a more robust framework. When the yield curve has already inverted and then re-steepened, leading economic indicators are declining, and the Sahm Rule is approaching its threshold, the probability distribution shifts heavily toward economic contraction.
The indicator is freely available through FRED and updates monthly with the jobs report. Setting up automated tracking takes minimal effort and gives you a structured way to assess recession risk rather than relying on narrative and sentiment.
One practical note: by the time the Sahm Rule triggers, defensive portfolio positioning should ideally already be in progress. The value is in watching it approach the threshold, not waiting for the official trigger. Markets price expectations, and the expectation of a trigger moves prices before the trigger itself.