Traditional economic indicators can’t predict the timing of a downturn, but newer forecasting methods are untested.

“The signals are mixed in a way that we haven’t seen before,” says Claudia Sahm, an economist and the founder of Sahm Consulting in Arlington, Virginia. “People say, ‘Historically when this happens, that happens, and then we go into a recession.’ That’s a good starting place, but that shouldn’t be the end place for the analysis.” The former Fed economist came up with her own real-time recession test. Called the Sahm Rule, it holds that when the three-month moving average of the unemployment rate rises by 0.5 percentage point or more relative to the low in the previous 12 months, a downturn has begun. (The current reading doesn’t indicate a recession.)