United Van Lines is one of the largest moving companies in the United States. Each year since 1978, it has reported its annual migration study, which tracks the share of outbound moves in interstate shipments for the entire 48 continental United States.
For Illinois, the share of outbound moves in total shipments has consistently been above 50 percent, meaning more households are moving out of state than into the state. Since 2006, that outbound shipments percentage has trended higher, and in 2011, Illinois "led" the nation on this metric, ranking as the No. 1 state. It slipped to No. 2 in 2012, barely trailing New Jersey (coincidentally, another state with pressing government fiscal strains).
The accelerating outmigration from Illinois isn't just a Midwest-to-Sunbelt issue. For example, chart here shows how Indiana has seen significant improvement since 2009 - in part as outmigration from Illinois has included moves to Indiana.