I made a comment about false membership numbers on the Trib a few weeks ago, and someone responded to me that if they can't find a member, they send the record to the missing file at church hq. I stated that they should publish the number of members in those files.
I found this, giving information from a letter the First Presidency sent out in 2012, but I wonder if anyone had information on those files, or if anyone had an idea of how many children under age 8 are on the records. Thanks

https://tech.churchofjesuschrist.org/forum/viewtopic.php?t=14787

The specific list in MLS 3.5.1 is:
Contact the occupants at the member’s last known address
Use postal services to find a forwarding address
Call any last known telephone numbers
Send an e-mail inquiry to any last known e-mail address
Contact known family members and relatives
Contact known friends, Church members, and full-time missionaries
Contact ward priesthood and auxiliary leaders
Check available online social networks
Obtain bishop's approval

Everyone knows LDS Inc's membership numbers are hugely inflated. I assume as a rule of thumb that the actual participating membership is about a third of their published numbers.

Good luck waiting for them to release numbers on how many members they have completely lost track of, or how many have resigned. While they have excellent data on both of those statistics, I doubt they will ever release them. Transparency is not something they do unless forced to.

As for number of children of record under 8 years old, simply looking at their last 8 consecutive statistical reports and add up the numbers they reported. It would be nice to know how many of those children of record actually get baptized when they turn 8, but they won't release that either. Anything less than 100% would embarrass them. I'm quite confident it is well under 100%.

They could report either average attendance per week, or number of people making a financial contribution each year. Either number would give a much better sense of how many participating members there are.

And yes, they are annoyingly persistent in tracking down "missing" members, which largely consists of people who wish they would f*** off and die.