The Guesses of Men, Mingled with Data

It’s time to play another round of wild guesses using calculation.  Let’s use LDS activity rate data to rough up a ballpark idea of what the LDS birthrate might be.

There’s an interesting study going around, using cellphone data to estimate actual church attendance as opposed to what people self-report.  Not very precise, probably only useful for comparing attendance across denominations.  The Deseret News has a write up.

The cellphone data would have it that .29% of the US population are fairly frequently attenders of LDS meetings.  The US population is 330 million, so that gives an Active LDS population of 957,000.

Meanwhile in surveys .87% claim to be fairly frequent attenders of LDS meetings.  That gives a Claimed Active LDS population of 2,871,000.

The Church has 6,868,793 American members on its rolls.  (The LDS USA facts and statistics page has nothing about births, perhaps because we are embarrassed by how low the figure is, as we probably should be.)

Our Activity Rate is 14%.  (That fits the wards I have been in.)
Our Claimed Activity rate is 42%.

In our TFR threads, we needed to know the Semi-Activity Rate, i.e., how many members on the rolls had enough connection with the Church to get their kids blessed.  We very roughly estimated that if we had a sad, bad but not catastrophic TFR in the mid 2s, we would have to have a Semi-Activity Rate of about 25%-39%.  We believe the Claimed Activity Rate should be somewhere in the neighborhood of the Semi-Activity Rate, which it appears to be.  Especially when you consider that the Claimed Activity Rate in the US is probably higher than elsewhere.

So our semi-spurious calculations are mutually confirming.  That’s nice.