Recently discovered that Redfin keeps track of users searching - source metro area and destination metro area.
https://www.redfin.com/news/data-center/migration/
So for those in out of state metros searching for Chicago area real estate, here are the top metros with the pct of those out of state metro searches from there. This is Q1 data:
1. Denver MSA: 11.2%
2. Los Angeles MSA: 5.3%
3. DC MSA: 4.9%
4. South Bend MSA: 4.6%
5. Boston MSA: 4.4%
6. NYC MSA: 4.2%
7. Bay Area: 3.6%
8. Minneapolis MSA: 3.3%
9T. Milwaukee MSA: 2.5%
9T. Seattle MSA: 2.5%
Just for reference, the highest in state metro in the searches is Rockford MSA at 3.6%. Interestingly, Chicago is the #1 MSA in the US with people looking to stay (i.e. people from the same metro searching properties in the same metro).