Being a parent that spanks, I view this as a non-issue and not up for debate.
There's an old saying - "Those who have no children know best how to raise them."
I have 5 children. I was raised in a family with 5 children. There are people at my wife's church with 9, 13, 10, 7, and 4 children. They all spank, and their children are wonderfully behaved.
Amish and Mennonite children are most often spanked, and are incredibly well behaved too.