I believe the return of polygamy will be necessary in coming years,particularly in places like Israel, which otherwise face catastrophic population declines
I don't really see how polygamy helps the birthrate. Unless there is an increase in births / woman it doesn't matter how many husbands / wife. Given the smaller number of adults in a polygamous marriage per child such an arrangement would seem to decrease the number of births. Perhaps Mr. Judd is assuming that polygamy would allow career women to have a home-maker spouse? Structurally, I would think that a line marriage ala Heinlein would work better, although (IMHO) the psychological aspects make it untenable in real life.