The fact of the matter is people with large familes do not pay alot if any income taxes.
You get a tax credit per dependent from the federal government. As frum people tend to have large families they pay little if any income taxes.
I think in 2016 the child tax credit is $1500 per kid, They is a tax credit, not a deduction meaning it comes off your tax liablity at 100% off ratehr than your tax bracket with is usually 15%, but could be 28%