If you're an Episcopalian, you may have been told that the "average age" of Episcopalians is 57.9 (and "rising rapidly"). Where does this number come from?
Well, it doesn't appear to come from anywhere, at least not from some actual study. It's also (in the mouths of other denominations) the average age of Methodists and of Presbyterians. And its pairing with an average age of US residents (a number given anywhere from 35 to 40) is utter nonsense.
The Canadian Census people do in fact collect pretty detailed info about religious affiliation and age. Their reports give an average age of about 50. There is a group called US COngregations which also does some study work along these lines. They report an average age for all US worshippers of about 50. A report they prepared specifically for the Methodists gives similar numbers.
These last two, by the way, show why the comparison with the average age in the USA is nonsense: they do not count children under age 15 at all.
I took the liberty of exchanging a few messages with C. Kirk Hadaway, Director of Research at The Episcopal Church Center. He wrote back:
"I have been unable to find the source of this number. I suspect that it is actually an estimate of adult Episcopalians from a national survey. Obviously, including children would lower the average age. I have tried to develop an estimate using known percentages of members 60 and over and demographic age distributions of the population. This is somewhat speculative, but I am sure that the actual average age is around 47 or 48 rather than 58."
"By combining Faith Communities Today data for the Episcopal Church with a census population pyramid I get an estimated average age of 49 in 2000. That is an estimate, of course, but any figure in the high 50s is highly suspect."
As for "rising rapidly", even if not a single Episcopal baby were born nor a single person converted, the average age could not rise by a year every year. The aging of the population is counterbalanced, to a degree, by the dying off of older members.
So why do people repeat these numbers? It's because they want to alarm people with the notion that their church is dying out. The reality is that large denominations tend to have population distributions that reflect that of the nation as a whole: a fairly uniform distribution of members across age groups. There is of course a dip in teen to 20s attendance, but its effect is not so dramatic as this.