Census: Cook County lost 10,000 people in 2015, most in nation

Cook County lost more than 10,000 residents in 2015, the largest number of any county in the nation, according to data released Thursday by the U.S. Census Bureau.

Overall, the Chicago area — which the census defines as including the city, suburbs and parts of southern Wisconsin and northwest Indiana — had a net loss of more than 12,000 people, the first year-to-year population decline for the region in a decade.

But Chicago demographer Rob Paral says that’s no big deal. The decline of 12,263 people for a region of 5.2 million is relatively tiny, and the losses are less than those seen in many regions in the Midwest and East.

“When you hear that Cook County lost the most people in the country, well, it’s also the second-largest county in the country,” said Paral, who works with nonprofit groups in the city.

The population figures released by the Census Bureau are estimates based on the 2014 population and the number of births and deaths and migrants. Paral said the Chicago area probably lost out slightly in each area.

The sagging U.S. economy has largely ended the flow of undocumented workers, Paral said, and Latino immigrants tend to be younger and have more children. A drop in the number of African-American residents in the Chicago area also contributed to the overall population decline for the region.

The region’s net population figure has generally been defined by declines in population in Chicago, buoyed by growth in suburban Cook and the collar counties, Paral said.

Development in collar counties, like DuPage, has slowed as communities become “built up,” Paral said, allowing room for fewer new residents. Older people have fewer children, and so the balance between the number of births and the number of deaths swings in “mature” areas, Paral said.

Census data released Thursday did not include city-level population estimates.

Younger people are moving away from the Chicago area, Paral noted, following national trends that show residents leaving the cold climates of formerly industrial areas of the Midwest and East to move to Sun Belt states. Ten of the 20 fastest-growing metro areas in 2015 were in Florida or Texas.

“Growth is nice; it’s hard not to like growth. But this is not Armageddon,” Paral said. “I’d say these numbers show the area is holding its own. It’s flat.”