Save for a couple of downstate counties, the northern part of Illinois brings home the bacon when it comes to income, according to a report out Tuesday.
The report, from the Transactional Records Access Clearinghouse at Syracuse University, looked at data from the Internal Revenue Service for returns filed in 2015. It ranked counties in Illinois and around the nation based on adjusted gross income, which includes wages and salaries as well as interest and dividend income.
The top five counties in Illinois were Lake, DuPage, Woodford, Monroe and Cook, in that order.
Lake and DuPage, which had average gross incomes of $104,583 and $89,707, respectively, come as no surprise in the top spots, said Lawrence Officer, an economics professor at the University of Illinois at Chicago. They are wealthy suburbs without much income diversity.
Cook County, on the other hand, is much more varied when it comes to income. Though still high on the list at No. 5, it has an average adjusted gross income of $71,593.
"You probably have the richest people in the state living in Cook County as well as the poorest people in the state," Officer said. "Just look at what rents would be along the Gold Coast compared to rents in the South Side."
Cook County jumped up four spots on the list from 2014, when its average adjusted growth income was $66,501.
Some of that growth could have come from Chicago's recent push for companies to relocate downtown from the suburbs and elsewhere, said Paula Worthington, a senior lecturer at the University of Chicago's Harris School of Public Policy.
Companies that have announced moves downtown recently, such as Beam Suntory, McDonald's and Motorola Solutions, cite a need to be close to the city for recruitment purposes — in other words, the employees they want to hire don't want to live in the suburbs anymore. If those employees do end up living downtown, that could affect the adjusted gross income, Worthington said.
Coming in close behind Cook in the rankings were McHenry, Will and Kendall counties.
In the No. 3 and No. 4 spots were Woodford County, which is near Peoria, and Monroe County, which is just south of St. Louis along the Mississippi River.
Nationally, McMullen County, Texas, took the top spot, with an average adjusted gross income of $303,717. This was puzzling to the report's authors as its best-known feature is Boot Hill Cemetery, one of several graveyards in the West so named because many of the interred reportedly were buried with their boots on.
Other high-ranking counties include Teton County, Wyo., and New York County, N.Y.