Kevin Drum notes two smart responses to the question of why home court advantage is so big, with one hypothesis pointing to the refs and another pointing to the idea that there are actually lots of differences from arena-to-arena.
The officiating issue is the most obvious one to point to, but it’s always seemed to me that the scale of home court advantage is too big to be explained this way. If this were the dominant factor, I think I’d expect to see teams’ point differentials be similar at home or on the road, but they’d have better records in the close games at home. But instead the effect seems big and systematic. And as Kevin says, what’s weird here isn’t just that home court advantage exists, but that it seems bigger than the advantage in football or baseball, even though in football the crowd can (and does) interfere with visiting team play calls and baseball stadiums differ dramatically from each other.