Needless to say, just because somebody is a homeowner wouldn't guarantee they wouldn't free-ride on their neighbors and let their own trash fly free as a bird.
But here's another perspective I found today, in which litter and other indicators of neighborhood risk causes low homeownership rather than the reverse, which is probably the more traditional perspective. It raised the obvious question in my mind of where the litter comes from in the first place, but it could be proximity to commercial strips or commuting hubs, I suppose.