It turns out that RV sales figures can be a pretty good leading indicator of the overall economy’s performance. Reporting from Elkhart, IN, “the capital of the recreational-vehicle industry,” Alana Semuels of The Atlantic writes that the RV industry is expecting 2017 to be a banner year—up 4.4% over 2016.

That’s obviously good for workers in the industry, and Semuels notes that there is very little automation used in RV production. But it could be good news for the rest of us as well. “When RV sales are doing well, the economy follows; when RV sales tank, the economy is soon to tank too,” she writes.

Semuels continues, “It makes sense that the RV industry is an accurate forecaster of the economy. People buy RVs when they have some extra money to spare. They also buy RVs when they feel financially secure enough to go on a long trip.” Further, RV sales indicate that credit is available for big-ticket purchases.

She notes that RV shipments bottomed out at 165,700 units in 2009 and rebounded to 374,200 in 2015. Estimates for 2017 are 438,000 units.