Why it matters
The label decides how policy is argued about. Once a downturn is officially a recession, the debate shifts from whether support is warranted to how much — which is why the dating is contested while it is happening and largely uncontroversial afterwards.
For markets, the more consequential point is that recessions are priced before they are declared. Asset prices reflect expectations, so the repricing occurs during the deterioration, not at the announcement. By the time a recession is formally dated, the information has usually been in prices for months. This is the mechanism behind the otherwise odd observation that markets can rise while the economy is confirmed to be contracting.
The distinction between a recession and a slowdown matters because the two behave differently. A slowdown is a lower rate of growth; a recession is a decline in the level of activity, and it tends to be self-reinforcing — falling demand reduces employment, which reduces demand. That feedback is why the transition between the two is treated as a threshold rather than a point on a continuum.
What to watch for
The two-quarter rule is a convention, not a definition. It is convenient and widely quoted, and it can classify incorrectly in both directions: an economy can meet it while employment holds up, or miss it while employment falls sharply.
Recessions are dated in arrears. Output data is published with a lag and revised repeatedly afterwards. A quarter can be reclassified from growth to contraction a year later, which means real-time recession calls are always provisional.
Indicators that lead and indicators that confirm are different tools. Employment is a confirming indicator: it deteriorates once a downturn is underway. An inverted yield curve is a leading one, historically associated with subsequent recessions but with a long and variable lag, and it describes what markets expect rather than what is happening.
Aggregate and sectoral conditions can diverge for a long time. Individual sectors routinely contract while the total keeps growing. Reasoning from one industry’s experience to the state of the whole economy is the most common source of premature recession calls.
In the United States the National Bureau of Economic Research maintains the official business cycle chronology; the Bureau of Economic Analysis publishes the underlying output data, and euro-area equivalents come from Eurostat and the CEPR’s dating committee.