My general view is bar fights are more common when there's not a perceived tendency of escalating into knife and gun fights. I don't have data to support it though.

I last saw a bar fight on the north shore of Kauai. I love Kauai, but locals have told me, "there's not much else to do at night other than drink and fight."

My personal observation is that it depends mainly on your culture (nationality?) relationship with drinking.

In some places, drinking is just something that do you do when you go out, in others, it seems like drinking is the goal of going out and they try to get drunk the faster the better.