Very true, but you just can't say that.
My idea would be to allow the first 2 children to be a tax deduction, 3rd neutral, more than 3 would pay extra taxes. This would be adjusted for rapes, twins or multiples. Plus, why not have deductions for childless couples? The problem arises trying to keep track of who the baby daddy's are. (some sarcasm here, but not really)
But there is a definite need to encourage small families. A hundred years ago families needed children to work the farms and such, plus half the children didn't live to adulthood. Today, children are a "want", rather than a "need".
Population growth rates can't continue as they are, and will eventually be regulated either willingly, or through mass die-offs. The carrying capacity of humans on Earth is somewhere around 2 billion, and even then with careful conservation.
People living on top of people is mentally and physically unhealthy, and leads to aggression.