But RV sales turn out to be a pretty good predictor too: When RV sales are doing well, the economy follows; when RV sales tank, the economy is soon to tank too.

Annual RV Industry Shipments

As the chart indicates, the RV industry has repeatedly fallen in advance of more widespread economic troubles. RV sales started dropping in 1999; the economy did not crash until 2001. Between 2006 and 2007, RV sales again dropped—this time 9.5 percent. The GDP still grew in that period, at an annual rate of 4.5 percent. But between 2007 and 2009 GDP growth slowed to 1.7 percent, and dropped 2 percent between 2008 and 2009. In fact, RV sales track closely with the Conference Board’s Leading Economic Index, an oft-used measure that pulls together a series of factors, including average weekly hours in manufacturing, building permits issued, average weekly claims for unemployment insurance, manufacturers’ new orders, stock prices, and average consumer expectations, to predict how the economy will fare.

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. Some Americans choose to spend their leisure time in RVs, and when Americans feel free enough to go on vacations and use their time to relax, and not work, it usually means the economy is ticking up.

In addition, shoppers often depend on credit to help them make these purchases, so a rise in RV sales means there’s credit available for big-ticket purchases. “We’ve been a leading indicator up and down for decades now,” said Kevin Broom, a spokesman for the Recreational Vehicle Industry Association, the trade group representing the industry. “It’s a large discretionary purchase that people borrow money to make.”

In some ways, RVs are the quintessential American-made item. They combine the home-building industry and the auto industry, and, as I learned on a tour of the Thor Motor Coach manufacturing facility, they’re made by skilled craftsman with little automation.

A RV begins as a chassis, essentially a flatbed truck, which RV companies buy from big automakers such as General Motors or Ford. Once Thor receives the chassis, workers add walls, as they would in a home, laying out where the bathroom will go, the bedroom, the living room. They install—by hand—foam insulation, cabinets, toilets, fixtures, wires, electrical outlets. When the living room part of the vehicle is completed, they add the fiberglass walls and ceilings. Each RV is made with a different floor plan and different add-ons, like walls that expand once the vehicle is parked to create more space. Each piece of this process requires specialized workers, as building a home does. Almost none of it is automated—I saw hardly any machines in the factory. And each RV is made after the factory receives an order from the dealership, Bogan told me, meaning that the number of vehicles a RV makes is a good sign of how many such vehicles people want.