What the Sahm Rule measures
The rule compares a recent average of the unemployment rate with its lowest reading over the preceding period. When the gap opens beyond the rule's threshold, the labour market is deteriorating at a pace historically associated with recession.
Its appeal is that it uses one widely published series, needs no revisions to work, and can be evaluated the moment the data is released.
Why economists use it
Official recession dating is announced well after the fact. The Sahm Rule was built to fill that gap with something simple, transparent and reproducible — a coincident indicator you can check yourself rather than a committee judgement you have to wait for.
Claudia Sahm has repeatedly cautioned that the rule is an empirical regularity, not a law, and that it can behave differently when labour supply is shifting for reasons unrelated to demand.
What the Sahm Rule does not tell you
It is not a market signal. Recessions and bear regimes overlap but are not the same event, and they rarely start on the same date. Equity markets price expectations; the labour market reports outcomes.
It is also coincident rather than leading. By design, it tells you a recession has probably started — not that one is coming.
- Coincident, not leading — it confirms rather than forecasts.
- Economic, not market — a recession call is not a regime call.
- Empirical, not causal — a historical regularity that can break.
How it fits alongside regime analysis
Macro indicators like the Sahm Rule supply economic context. Regime classification reads market structure. Used together, one tells you what the economy is doing and the other tells you what the market is doing about it.
RegimeSignal™ carries the Sahm Rule in its Macro Monitor terminal as informational economic context, separate from regime signal access.
Frequently asked
What is the Sahm Rule?
The Sahm Rule is a real-time recession indicator that compares a recent average of the unemployment rate with its lowest recent reading. When the gap exceeds the rule's threshold, a recession has likely already begun.
Who created the Sahm Rule?
It was developed by economist Claudia Sahm, formerly of the Federal Reserve Board, as a simple real-time alternative to after-the-fact recession dating.
Is the Sahm Rule a stock market signal?
No. It is an economic indicator about the labour market. Recessions and bear market regimes overlap but are distinct events that rarely begin on the same date.
Is the Sahm Rule leading or coincident?
Coincident. It is designed to confirm that a recession has probably already started, not to forecast one in advance.