I considered the statistics, like the lack of population growth Chicago has recently experienced.  

(I'm a very data driven person so if you have statistical support that would also be awesome!)

I really enjoyed Dave Meyers post here https://www.biggerpockets.com/... as a data guy trained in biological statistics I am much more data driven.

Of course, this information can vary by the exact city or area, considers different factors which may be minor, statistics can be interpreted differently, etc. 

For more information, and statistics, as well as sources. 

I saw a crazy statistic that most realtors ever were birthed in the last 2 years and most realtors ever are deactivating their license right now 

If we reference housing statistics from the U.S.

I think its hard to find great statistics on what vacancy is "normal" for most markets and rental unit types, but if you budget for a certain amount of vacancy that you're comfortable with and then identify areas where you can work on lowering your vacancy you are actively tacking and managing the issue/cost. 

October 2022 Housing Market Update for Austin, TX MSAOctober 2022 statistics have been released for the Central Texas Housing market.

Keeping an eye on the statistics tells us about the present, but can't reliably predict the future.I've helped several investors buy Airbnbs throughout the Valley, so it is definitely an issue I keep track of.