re: #4 Mostly sane, most of the time.

You mean that mothers of nine children don’t have time for a 45 minutes survey?

I’m shocked.

Also—how hard is it to figure out that if people in Group A are all having 7-10 kids, and people in Group B are having, maybe, two or three, at most, that Group A is shortly going to be much bigger than Group B?

The Jewish People Planning Policy Institute (What a Soviet-sounding name!) relied heavily on the results of the “National Jewish Population Survey” published in 1990. They made their own survey 10 years later based on the results from their telemarketing calls, but their sampling methods, surprise, surprise! yielded utter crap for data.