I forget when and where it was in which, as a reporter, I heard a stunning lecture on the impact of birthrates and basic demographics on the rise and fall of religious institutions in the United States and elsewhere.What made the lecture so interesting was the connection the speaker — it might have been the United Methodist thinker Lyle Schaller — made between traditional forms of religion and higher birth rates (and, correspondingly, between liberal forms of religion and much lower birth rates). Think about the recent decline of mainline Protestantism. Think about churches in Europe.