The official designation of a recession comes from a committee at the National Bureau of Economic Research (NBER), a private, nonprofit research organization.
The committee considers a wide range of economy-wide, monthly data points, but the NBER views GDP as “the single best measure.”
The committee calls a recession once there is a significant decline across these measures for more than a few months.
The NBER’s official designation of a recession, then, doesn’t happen until there are several months of data, allowing it to be sure both that a recession happened and when exactly it started.
In other words, as Voronoi notes, the NBER looks backward, not at the present moment.
Using this measure, here's a few insights:
In other words... there used to be more 'official' recessions.