U.S. population growth slowed over the last decade to its lowest rate since the Great Depression. The U.S. population is aging rapidly. While baby boomers have started to hit retirement age, challenging economic circumstances have caused many younger Americans to postpone having a family — and this was before the pandemic made conditions even more difficult.
While the overall U.S. population still increased in the past decade, some parts of the country reported population decline, mostly due to people moving away. As people move away to either retire or to take on a new job, natural population increase (births minus deaths) has not been enough to offset net migration losses. Nearly every state has at least one county where the population declined significantly from 2010 to 2020 — in some cases by well over 10%.
Economic opportunity — or lack thereof — can be a major factor that causes people to relocate. Most of the fastest shrinking counties in every state have an unemployment rate and a poverty rate greater than or equal to that of the state itself. Other factors, like prevalence of violent crime, lack of recreational activities, and other less desirable qualities can also be factors that cause residents to leave an area in droves.
The fastest shrinking county in Illinois is Cass County. The county’s population declined by 12.6% from 2010 to 2020. The population of Illinois overall decreased by 1.9% during that same time period, and the U.S. population increased by 6.7%.
Cass County’s population declined by 1,716 people during the decade, from 13,641 in 2010 to 11,925 in 2020. This is due in part to negative net migration as 2,007 more people moved away from the county than moved to it during that decade.
To determine the fastest shrinking county in every state, 24/7 Wall St. reviewed data on population from the U.S. Census Bureau’s Population and Housing Unit Estimates Program. Counties were ranked based on the total population change from 2010 to 2020. Only counties with at least 10,000 residents in 2010 were considered. Data on population change due to natural growth and net migration also came from the Census Bureau PEP program. Data on median household income and poverty rate came from the Census Bureau’s 2019 American Community Survey and are five-year estimates. Data on unemployment for May 2021 came from the Bureau of Labor Statistics and are not seasonally adjusted.
|State||County||Total population, 2010||Total population, 2020||Total population change, 2010 to 2020|
|Alaska||Kodiak Island Borough||13,606||12,992||-4.5%|
|Colorado||Las Animas County||15,506||14,420||-7.0%|
|Delaware||New Castle County||538,496||561,531||4.3%|
|Nebraska||Box Butte County||11,308||10,696||-5.4%|
|Nevada||White Pine County||10,026||9,466||-5.6%|
|New Hampshire||Coos County||33,052||31,174||-5.7%|
|New Jersey||Cumberland County||156,610||147,008||-6.1%|
|New Mexico||Colfax County||13,751||11,927||-13.3%|
|New York||Delaware County||47,962||43,938||-8.4%|
|North Carolina||Northampton County||22,104||19,088||-13.6%|
|North Dakota||Walsh County||11,126||10,437||-6.2%|
|Rhode Island||Bristol County||49,842||48,350||-3.0%|
|South Carolina||Allendale County||10,419||8,331||-20.0%|
|South Dakota||Yankton County||22,438||22,742||1.4%|
|West Virginia||McDowell County||22,108||16,916||-23.5%|