I don't have any stats in front of me, but I know in my personal experiences all the people I've known who were physically "reprimanded" by their parents ended up with drug/alcohol problems or even (in some cases) run-ins with the law.
I'll be happy to explain that to you when you can explain to me why it's only been a 'problem' in the last 30 years that kids who are physically "reprimanded" by their parents end up with drug/alcohol problems or run-ins with the law.
Before the 1960's generation had children, EVERY child was spanked or punished physically in some way and yet these "problems" were not an issue then. The answer is that it has nothing to do with how people punish their children, it's the result of how our society functions as a whole and the direction it is taking.
Bill Maher made some brief comments on it in a hbo special, calling it the feminization of society, where safety becomes more important than fun and manly behavior is villified. Every time we look at our children doing something inane that we used to do all the time and tell them to stop it because they might get hurt, we're depriving them of the opportunity to learn something that is beyond the simple 'why they shouldn't do that'. The same goes for these pacifist parenting schemes. "Talk to your child." "Send them to the naughty corner." "Give them a time out." If they grow up like that, then when they run into a situation where someone actually DOES hit them, they'll bawl like the pussy you turned them into, which will look pretty foolish at 33.