Things were looking good for the Episcopal Church in 1966, when its membership hit 3.6 million — an all-time high. Then the numbers began to decline, year after year and decade after decade. At the moment, there are 1.6 million or so Episcopalians.

Why is this happening? Episcopal Church leaders have been asked that question many times, because it’s a valid and important question.

No one has ever given a more concise — bold, even — answer than the Rt. Rev. Katharine Jefferts Schori, when she said down for a “State of the Church” chat with the New York Times Magazine soon after her 2006 election as national presiding bishop. Here is the crucial exchange:

How many members of the Episcopal Church are there in this country?

About 2.2 million. It used to be larger percentagewise, but Episcopalians tend to be better-educated and tend to reproduce at lower rates than some other denominations. Roman Catholics and Mormons both have theological reasons for producing lots of children.

Episcopalians aren’t interested in replenishing their ranks by having children? 

No. It’s probably the opposite. We encourage people to pay attention to the stewardship of the earth and not use more than their portion.

In other words, her critics said, Episcopalians are too smart to have lots of babies (unlike Catholics and Latter-day Saints) and, besides, most members of this flock have theological reasons not to procreate.

What we have here is a classic example of the formula that I keep writing about here at GetReligion, which I state this way, offering a third factor to a familiar equation: Doctrine equals demographics equals destiny.

That brings me to this new headline at the Times:

America’s Biggest Economic Challenge May Be Demographic Decline

Slower growth in the working-age population is a problem in much of the country. Could targeted immigration policy help solve it?

Here is the rather sobering overture: