DY,
The schools near me cost around $15,000 or more per kid.
But lets use Lakewood values – around $5,000. Average family size is what, 8? That’s $40,000 in tuition, after tax. You are probably in the 25% tax bracket at that point so $53,000 salary. Are you telling me in Lakewood the average 2nd salary is $53,000? I find that doubtful.
As to incremental costs – that’s true if you are talking about 1 child. If a family can afford to put 3 kids in the local Yeshiva, but have 6 kids or they have a 7th, the family cannot pay more for the 7th child at all. At a certain point, there needs to be an additional class to host the increasing population.
Yes, I believe many parents have the ability to homeschool their kids. I think most don’t want to, so they choose to live off of tzedaka instead.