The future of spanking
Even in its milder forms, spanking is not recommended as one of the discipline consequences tools.
Spanking has no future with a child. The older the child, the more force needed to make spanking unpleasant. Spanking can escalate to battering and make a child afraid and resentful of authority.
Spanking encourages children to use aggression to solve problems. Parents who spank are in a difficult position to discourage their children's hitting. With spanking, children have an unacceptable model for solving problems.