Dead or unemployed?
The unemployed can be parsed from the dead when their social security numbers pop up again as active in the system...ie registering for unemployment due to disaster related loss of job, applications for relief or if such people find another job and enter the work force again and if their bank accounts show recent vs no activity over past 6 weeks.
The dead cannot be truly hidden if their social security numbers and the accounts they are attached to show no activity versus the ssn’s of those who are still alive. Lack of activity in bank accounts of those persons missing in that area will also stand out like a sore thumb!
It will not be exact but a study of such activity will show the scale of the numbers of the missing and the dead!