Brown County was an oasis in a population desert in 2021, the only county in west-central Illinois — and among just 21 statewide  —  to see an increase in people calling it home.

Annual estimates by the U.S. Census Bureau of resident population between April 1, 2020, and July 1, 2021, projected 177 more people lived in Brown County during that period than when the 10-year Census was conducted in 2020. That took the county population to 6,421 from 6,244, according to the U.S. Census Bureau estimate.

Like the majority of Illinois counties that experienced a rise in population — largely clumped in east-central, southeast or northern parts of the state — Brown County’s growth spurt was attributed to domestic migration. That term is used for the movement of people within locations in the United States.

While 58% of the counties nationwide had population growth, smaller counties saw more net domestic migration last year than metropolitan areas, according to the U.S. Census Bureau.

The remainder of west-central Illinois’s eight-county fingerprint lost population last year — as did 81 counties total in Illinois.

Scott County was among them, but its loss stands out from others as an outlier because its drop of 113 residents, to 4,836, was attributed to migration loss. While there were 42 more deaths than births in the county last year, the most significant loss was from 71 people moving from the county, the estimates show.

Other west-central Illinois counties’ declines were driven more by natural change.

In short, the number of births did not outpace the number of deaths.

That dynamic, combined with migration, resulted in a population decline in Morgan County of 309, to 32,606. Cass County fell 269, to 12,773, and Greene County by 142, to 11,843, according to the Census Bureau figures.

Morgan County, for example, recorded 422 births but 600 deaths during the period — a difference that far out-paced its growth of new residents.

Other west-central Illinois population drops by county were: 68 in Calhoun, to 4,369; 179 in Jersey, to 21,333; 561 in Macoupin, to 44,406; 121 in Pike, to 14,618; 1,609 in Sangamon, to 194,734; and 59 in Schuyler, to 6,843.

The counties were among 2,297 nationwide — 73% of the 3,143 in the U.S. — that experienced natural decreases last year, according to the Census Bureau. That percentage has risen sharply, from 45.5% in 2019 and 55.5% in 2020.

The agency concludes that fewer births, an aging population and increased mortality — intensified by the pandemic — contributed to that growth.

Statewide, Cook County saw the biggest percentage decline, 1.7%, last year. Downstate counties averaged 0.4% losses.

That shows “Illinois is still bleeding people from every corner of the state,” said Ted Dabrowski, president of Wirepoints, an independent organization that researches the state’s government and economy. “The state’s 81 shrinking counties lost 121,000 people, while the 21 counties that grew gained just 7,400 people.”

While pandemic restrictions may have played a part in the decline, it’s hard to determine how significant an effect they had, according to Wirepoints.

“But what we do know is that Illinois lawmakers have made no effort to make Illinois more livable,” Dabrowski said.

The Illinois Policy Institute, a Libertarian-leaning think tank, said population declines can contribute to lower economic prospects for the state, which can lead to a continuous downward spiral.

“Illinoisans have historically chosen to leave the state for better housing and employment opportunities, both of which have been made worse by poor public policy in Illinois,” said Bryce Hill, a senior research analyst at Illinois Policy Institute.