I can’t see anything obviously wrong in that reasoning, but in Italy that situation has more-or-less obtained for decades and I can’t see any sign of such a process happening.
I guess what’s happening is some process preventing the standards of some members to fall much below the standards of the rest of the society. (If you know your children will be ostracized by their peers, making their life much harder, unless they wear expensive clothes, have expensive toys, etc., then you might not want your children to wear cheap clothes and have cheap toys, even if in isolation they’d enjoy them just as much as expensive ones.)
It’d be interesting to know what is going on. If you argue from a sort of Malthusian ideological-lowering-of-subsistence-wages, that doesn’t explain it since the subsistence wage is still way below the regular wage and ought to allow indefinite over-reproduction of the subpopulation. And these subpopulations often isolate themselves from the world and denigrate it as much as possible, so the world’s standards shouldn’t matter too much to them.
My own suspicion is that there’s some sort of diseconomy of scale to these subpopulations: they grow like gangbusters but the growth tapers off until total retention rate matches overall population growth rate.
But I don’t know this for sure. I don’t know that members start leaving the large subpopulation for the main population at sufficient rates to offset the fertility, or why the leaving rates would change as the group grows. Certainly the Amish seem to be continuing to grow without a problem. It may be that there’s a certain formula (decentralization?) which only a few have hit upon recently.
I can’t see anything obviously wrong in that reasoning, but in Italy that situation has more-or-less obtained for decades and I can’t see any sign of such a process happening.
I guess what’s happening is some process preventing the standards of some members to fall much below the standards of the rest of the society. (If you know your children will be ostracized by their peers, making their life much harder, unless they wear expensive clothes, have expensive toys, etc., then you might not want your children to wear cheap clothes and have cheap toys, even if in isolation they’d enjoy them just as much as expensive ones.)
It’d be interesting to know what is going on. If you argue from a sort of Malthusian ideological-lowering-of-subsistence-wages, that doesn’t explain it since the subsistence wage is still way below the regular wage and ought to allow indefinite over-reproduction of the subpopulation. And these subpopulations often isolate themselves from the world and denigrate it as much as possible, so the world’s standards shouldn’t matter too much to them.
My own suspicion is that there’s some sort of diseconomy of scale to these subpopulations: they grow like gangbusters but the growth tapers off until total retention rate matches overall population growth rate.
But I don’t know this for sure. I don’t know that members start leaving the large subpopulation for the main population at sufficient rates to offset the fertility, or why the leaving rates would change as the group grows. Certainly the Amish seem to be continuing to grow without a problem. It may be that there’s a certain formula (decentralization?) which only a few have hit upon recently.