Cook County’s loss of taxpayers and taxpayer dollars is the gain of collar counties, including Kane, according to Internal Revenue Service data and a report by the Illinois Policy Institute, a non-profit think tank based in Chicago.

The article puts the migration onus on a variety of pending and previous tax increases, but whatever the reason, the data is clear that people and businesses are moving from Cook to the collar counties. Here’s the data for the years 1992 to 2011, sourced from the IRS:

1. DuPage County won a net of 104,904 taxpayers who took more than $4.6 billion in taxable income with them.
2. Will County won a net of 84,170 taxpayers who took $4.4 billion in taxable income with them.
3. Lake County, Illinois, won a net of 67,906 taxpayers who took $4.1 billion in taxable income with them.
4. Kane County won a net of 41,364 taxpayers who took $2.2 billion in taxable income with them.
5. McHenry County won a net of 35,200 taxpayers who took $1.7 billion in taxable income with them.
6. Lake County, Indiana, won a net of 35,296 taxpayers who took $1.3 billion in taxable income with them.

According to the article, Cook County lost 370,000 taxpayers to its collar counties and Lake County, IN, and those taxpayers took about $18.3 billion in taxable income with them when they left.

The population change shouldn’t be too much of a surprise. Northern Illinois University’s Center for Governmental Studies came out with a report in early June that showed some of the areas that are growing in population and some that weren’t. Although Cook County’s population grew during the time period of 2010 to 2014, most of that was from births. The NIU study shows that 152,538 people migrated out of Cook County during that time span.

Kane County Population Series

• Monday: Kane County 3rd in Illinois Population Growth
• Tuesday: Elgin, Aurora, Pingree Grove, Huntley Among Fastest-Growing Communities in Illinois
• Wednesday: Where Is Kane’s Population Growth Coming From?
• Thursday: Where Are Illinois Residents Migrating?
• Today: Illinois’ Population Decline; What Does It Mean?