You actually gave one, no, two, reasons why I don't believe in this kind of punishment. There are many parents who use this form of punishment. It was used on me and my brothers when I turned 12 or 13, but, to tell you the truth , it always allowed us to get away with "cheating" out of the punishment behind our parent's backs. My father worked full time, and my mom at home, but they were too busy to constantly watch us. Of course it only became easier after my mom had to work full time in an office as well.
I grew up in an abusive family. My father would do more than just beat us. He would come home from work always in one of his mood swings. His excuse was either someone pissed him off at work or he was tired (the ramblings was the tell), but the worst was not the beatings. It was what was said during them, and how the beatings took place.
When one looks at all the kids today that do not get corporal punishment one can see that they are whiny, slightly obtuse, and many times abusive towards their parents (in extreme circumstances even physical).
Anyway, to get to the point, despite what these psychologists, who are part of a VERY young scientific community, say, it is not bad to hit your kids when they were naughty. Despite my father being abusive, I believe firmly that corporal punishment, done right, teaches better integrity, helps them remember what they did wrong (pain is a good stimulant of memory, just look it up a bit in the scientific journals), and builds character (psychologists whine that kids that are beaten when young are usually more aggressive, but considering the world we live in, and all the whining going on around us, I'd say that is a good thing).