Lots of child psychologists and teachers believe that parental involvement is key to stopping a child becoming a bully (eg parents actively engaging with their kids welfare) and the most common thing that stops parents being involved in bringing up their kids is poverty. Trying to fix poverty is weirdly controversial.

Is there some kind of consensus that bullies are predominately poor? Even if thats true on a quantitative basis, the bullies that count are the ones with social standing.

Some even make it to president. Some even think, being a bully is mandatory for any higher position in politics ..

I wonder if it's better in old style schools not segmented by age. Then faster physical development gives much less of an advantage, and the immature younger students can have their behavior moderated by the older, hopefully more mature students. And older siblings can watch out for younger ones.

Every study I've ever read says this is much better.

I haven't given this topic a lot of thought, but at first glance it sounds like one of the very hardest problems imaginable to solve? It's hardwired deep into human psychology, and you have limited ways of affecting - or even communicating with - school-aged kids.

I think we have several millennia of proof we cannot.