Population Charlotte

The population for Charlotte (METAREA 1521) shows a decrease from 2,458,989 in September 2019 to 2,348,221 in September 2022 3 years later (used 3 years to compare to pre-pandemic), which cannot be correct. Why would population go down or is the data unreliable? Even on a T12 yearly basis it went down.

I presume you’re getting this data from the CPS since you are looking at September. Plotting the population of the Charlotte metro area over time (see screenshot below), there is a lot of monthly variation in the totals of the CPS person weights, just due to sampling error. The magnitude is greater than the difference you’re seeing between 2019 and 2022. You can also see that the noise is much larger in magnitude than any trend, and there’s no apparent decrease in population if you look at the entirety of 2022. If you’re going to compare the population of metro areas over time, I suggest either pooling multiple CPS samples or using the ACS, which has a much larger sample size.