Gray’s Papaya hot dog restaurant in Manhattan has served up beef franks to the hungry and frugal masses for the past five decades.

But the bustling business off 72nd and Broadway isn’t just an iconic New York City bastion for cheap eats — it also moonlights as an unofficial economic indicator.

When hot dog sales there see a dramatic pickup — particularly the two-frank-and-tropical-drink “Recession Special” — it’s usually a signal that folks have fallen on harder times, owner Rachael Gray told CNN.

“We noticed a big uptick around 2008-2009, when everything was collapsing (amid the Great Financial Crisis), and we are feeling the same thing right now — to a lesser extent, obviously, but the pattern is the same,” she said.

There are scores of traditional, time-tested gauges of the US economy’s health and its trajectory: Federal data on employment, production, spending, income and other critical areas factors heavily into the calculus of the National Bureau of Economic Research, the official arbiter of recessions, when it dates business cycles.

(The NBER’s declarations, by the way, don’t happen in real time. They often come months, and sometimes not for two years, after a recession has already started.)

Still, as it stands now, while some barometers indicate the US economy is slowing, recent data has shown that it’s still growing, consumer spending remains strong and the unemployment rate isn’t yet tripping alarm bells.

Customers eat hot dogs outside Gray's Papaya in New York City, on September 26.