Punishing kids is counter productive

"the US Department of Education counted 130,000 expulsions and roughly 7 million suspensions among 49 million K-12 students—one for every seven kids. The most recent estimates suggest there are also a quarter-million instances of corporal punishment in US schools every year.
But consequences have consequences. Contemporary psychological studies suggest that, far from resolving children’s behavior problems, these standard disciplinary methods often exacerbate them. They sacrifice long-term goals (student behavior improving for good) for short-term gain—momentary peace in the classroom."

Sources:
https://www.facebook.com/parentinggently/
http://www.motherjones.com/politics/2015/07/schools-behavior-discipline-collaborative-proactive-solutions-ross-greene/