One study that might actually be of interest is to track the development of the bullies vs the bullied and see who winds out ahead in the game of life.
The Wall St Journal recently had an article in which a journalist tracked down the bully who had tormented him throughout childhood. I was terribly disappointed in the story, but the WSJ got a lot of reader mail praising it, so maybe I missed something.
The short answer: The bully died in his 30's. He was alone, without friends or resources. A shattered shell of a man. Now, if you're looking for any sense of Karma, that the guy got what was coming to him, I think you need to read the Long answer, to find out if bullying can pay off later in life.
The long answer: The bully never stopped bullying people. He went into construction and became rich and successful. He was a horrible boss, but he got the jobs done, and apparently his customers appreciated this. He had fancy clothes, fancy cars, a big income, and lots of women. He was riding high until -- one of the women gave him AIDS. He got sick, lost his money and died.
Now, is this evidence that bullies get what's coming to them? Or is it evidence that bullies can make out pretty well in our society -- unless they catch a communicable disease?