Originally Posted by wig

But that assumes that atheists will automatically not have children that become theists and that theists will automatically not have children that become atheists.

I may be incorrect about this, but I understand that religious belief is growing fastest in the poorest and least educated parts of the world and slowest (perhaps even declining) in the richest and most educated parts of the world (in general).

If correct, it follows that education and wealth (again, in general!) may be a better indicator of the growth or decline in religiosity.

Personally, I find this a better explanation and indicator. IOW, in general, people who are the least well off will more likely make appeals to a higher power.