Why do we care how Robertson County, Tenn.; Pontotoc County, Miss.; Boone County, Ill.; and Elkhart County, Ind., are doing, or how much they have in common?

Because, in addition to manufacturing big-ticket luxuries beloved by the middle class, they have predicted every recession since 1975. Their 12-month average employment numbers always fall before a wider downturn begins.

What can we learn from them today? Our most recent numbers, from early this year, show them bending south, but not cratering. But local officials remain upbeat, and it’s too early to tell if the counties are preparing to slip ahead of a downturn, or if any hint of weakness is just a temporary hiccup.

We focus on these counties because, unlike many others that weaken before the broader economy, they have shown strong job growth in recent decades. Their past downturns were exceptional and thus struggles there might plausibly signify something bigger. And the implications are immense. These four counties won’t determine the next election. But the economy they inform us about will.

Each enjoyed a strong recovery after the Great Recession. Officials we spoke with often said anyone who wanted a job could get one. Employers expanded and there was more hiring on the horizon. But there are reasons for concern. The products they build — furniture, appliances, jeeps, motor homes and boats — are the types of products that get hit first when consumers tighten their wallets.

In Robertson, losses in manufacturing have been partially offset by strong seasonal hiring at warehouses. Pontotoc has flatlined since its 2016 peak, but hiring seemed to recover slightly early this year. RV woes are pummeling Elkhart. It lost about 5,000 jobs between late 2018 and early 2019. A key factory in Boone laid off a shift earlier this year but we don’t yet have enough data to evaluate whether it slowed the county’s rapid growth.

At this early date, different sources show different degrees of economic distress in the counties we examined. (For this analysis, we use the Labor Department’s Quarterly Census of Employment and Wages. It gives us detailed data on jobs at establishments in each county from 1975 through March of this year.)

A pattern emerges

Together, these four counties are examples of places that are so exposed to the whims of the wider economy that they sneeze long before the rest of the country realizes it has caught a cold.

All manufacture big-ticket discretionary consumer goods and depend on just a few big employers. They lack a large urban consumer base of their own and have deep trade links outside the immediate area.

“All these big employers make things that are very susceptible to a downturn,” said economist Michael Hicks of Ball State University in Muncie, Ind. And each major employer supports myriad services and suppliers, “so if you idle or slow down one factory’s orders, it hits everything from the gas and electric companies, to the soda-machine stockers, to the folks who cater meals or clean the place.”

To be sure, predicting the future is never as easy as simply selecting counties based on past growth patterns. We’re not building a statistical model; we’re just looking for clues in successful-yet-vulnerable places that are typically overlooked.

Robertson County, Tenn. (71,012 residents in 2018)

Like much of Middle Tennessee, the economy of Robertson County once rested on the twin pillars of tobacco and whiskey. But Springfield (16,957 residents) and some of the other 10 small municipalities in the county diversified into manufacturing in the 1960s and ’70s, when the county had fewer than a quarter as many workers.

It’s been among the fastest-growing 10 percent of county workforces ever since, but its home-goods factories — local workers make thousands of gas, electric and induction ranges a day for Swedish appliance giant Electrolux — and booming residential construction put it at the mercy of the housing market.

Appliances and furnishings are a leading indicator, chief county economic development officer Margot Fosnes said. “They’re a big-ticket item for a household. If you’re not sure you’re going to have a job, you’re probably going to put that off.”

Robertson’s workforce peaked in 2017, according to the 12-month average, and appeared to bottom out in late 2018. Other data hints that, in the past year, Robertson’s employers have been adding jobs again.

Earlier this year, Electrolux announced it was consolidating all of its U.S. cooking manufacturing sites into the one in Robertson County, where it is investing $250 million to modernize and automate the factory. The renovation isn’t expected to affect job growth.

Robertson recently hit an important milestone: Transportation overtook manufacturing as its biggest employer. The category includes warehouses for retailers such as Macy’s and Lowe’s, which have arrived to take advantage of the county’s strategic location along two interstate highways just north of Nashville (669,053 residents).

“The downtown area is booming,” said Zena Smith, 84, who worked in real estate in the county for decades and became the first woman to lead its chamber of commerce. “The old square that was dead in the ‘80s has now come to life. We actually have our own brewery with eight craft beers. We have health food stores.”

Seventy-year-old Don Eden, a county commissioner from White House (12,506 residents), built a cherry-picker and boom-truck manufacturing company from scratch. He said the county thrives because it’s close to Nashville, yet has room for affordable residential developments. “Things have really been good since the recession,” he said. “And they’re really good right now.”

Employers are so hungry for workers that they’re paying bonuses to attract high school graduates and training up unskilled workers, Eden said. “If a slowdown comes, we will feel it but it won’t be drastic."

Pontotoc County, Miss. (31,833 residents)

In northeastern Mississippi’s hill country, just off the interstate linking Atlanta to Memphis, Pontotoc County makes furniture. A lot of furniture. One of the world’s largest furniture factories, a boxy, off-white Ashley Furniture plant in tiny Ecru, employs several thousand workers from around the region.

Like the gas ranges of Robertson County, Pontotoc’s home furnishings are sensitive to the fortunes of U.S. consumers and the housing market that serves them. But Pontotoc Chamber of Commerce chief Ellen Russell is working to change that.

Russell was born in Pontotoc, much like her parents, grandparents and the state’s entire U.S. Senate delegation for the decade ending in 2018. (Republican Sens. Thad Cochran and Roger Wicker were both born there. Like the other counties we examined, Pontotoc went for Trump in 2016). Russell gets riled up when she’s talking about its economy and community.

“We’re getting more diversified to make sure that 2008 doesn’t come back to bite us in the butt again,” Russell said. “The main street is the heart of the community, and if you don’t keep the heart beating good you’re going to have problems,” she added later.

Boone County, Ill. (53,577 residents)

Belvidere is Boone County’s largest city. Mike Chamberlain, whose prairie pragmatism tempers his mayoral boosterism, attributes the area’s recession sensitivity to three words: Fiat Chrysler Automobiles.

The company pays about 4,000 workers to make Jeep Cherokees at a nearly 5-million-square-foot plant there. The county has attracted several new industries since the last downturn, but even after laying off an entire shift earlier this year and shifting production to China, Fiat Chrysler remains Boone’s largest and most influential employer.

“When the plant is up? Things are groovy. When the plant is down? Things are not,” Chamberlain said.

Like Robertson, Boone benefits from its strategic location — it straddles a major interstate and sits minutes from another. The town is adding jobs at a breakneck pace, training up less-skilled residents and attracting experienced workers from around the region, but officials are still pushing to diversify its economy.

“Our small- to medium-size homegrown businesses have blossomed,” Chamberlain said, but “I think we are going to see some type of a recession soon — it’s overdue. It’ll affect the automotive sector. We’ve seen a minor slowdown in sales but it hasn’t been drastic just yet.”

Pamela Lopez-Fettes, executive director of local economic development organization Growth Dimensions who has been in Boone County for 17 years, said the county had been boosted by the arrival of major auto suppliers such as Magna Exteriors (816 employees, according to Lopez-Fettes) and Yanfeng (300 employees), but that growth had slowed amid trade worries.

Elkhart County, Ind. (205,560 residents)

Elkhart County makes most of the United States’ motor homes and travel trailers. But sales dropped about 20 percent so far this year, according to the RV Industry Association. RVs are one of the biggest-ticket middle-class luxuries, and as such they tend to be one of the first spending categories to get cut when the economy’s fixing to nose-dive.

Bonus: Monroe County, Tenn. (46,357 residents)

In 1980 and 1981, the country slid into recession twice in rapid succession. In our analysis, we count both recessions separately. But if you combine them and filter out small and volatile counties with fewer than 10,000 workers, another place rises toward the top of the list.

Monroe County straddles Tellico Lake, a meandering reservoir southwest of Knoxville. The county’s factories produce many of America’s recreational watercraft, from 20-foot wakeboarding boats by MasterCraft to 65-foot yachts by HCB. Boats, like RVs, are the sort of luxuries that get cut first when the middle class feels the squeeze, Hicks said.

There’s little indication of a slowdown in Monroe yet.