In the year since Illinois passed a record-setting, permanent income tax increase, the state saw its highest population loss in recent history. Data on national population trends released from the U.S. Census Bureau this morning show Illinois shrank by more than 45,100 residents – the second largest decline in the nation. This population loss was driven primarily by an exodus of residents to other states. From July 2017 to July 2018, Illinois lost more than 114,000 residents to other states on net. This troubling trend comes as the number of births in the state is declining. If this continues, Illinois is projected to lose one or two of its 18 seats in U.S. House of Representatives following the 2020 Census. According to previous Census data, migrants leaving Illinois tend to be prime-working age adults, educated and seeking work. 

The data reveal the following highlights:

• Illinois’ population shrank by 45,100 people

• 114,154 Illinoisans left for other states on net

• Illinois loses 1 resident every 4.6 minutes to other states

• None of Illinois’ neighboring states saw population losses

• Illinois has had one of the most severe declines in births in recent years 

• Since 2010, Illinois has had the worst population loss in the nation, in raw terms
• Illinois’ population loss over the last five years is equivalent to losing the entire city of Joliet, Naperville or Rockford (the third-, fourth- and fifth-largest cities in the state respectively)

• Over the past year, states with a progressive income tax lost 293,000 people to other states, while states with no income tax gained 339,000 residents from other states