Bh, my completely unscientific and unverifiable method - my own eyes - agrees completely with your original post.
All the old timers here are groaning
Back when I lived in the hood, mid 80s, there were very very few that had a/c, were lucky to have one car, NO cable...
Now when it's hot the streets are darn near empty (of people anyway), most have a car, most have cable and a few tvs ....
Not to say there isn't any poor but the bar has definately moved.
Pete