The Sahm rule, a rule of thumb popularized by economist Claudia Sahm, says that if the average of the unemployment rate over three months rises a half-percentage point or more above the lowest the three-month average went over the previous year, the economy is in a recession. Over the past three months, the unemployment rate has averaged 4%—0.4 percentage point above the three-month average low of 3.6% over the past year.