The difference of income between top 1% and bottom 1% in an area is as useful/relevant as talking about the _average_ income in said area. If some area has some

The difference of income between top 1% and bottom 1% in an area is as useful/relevant as talking about the _average_ income in said area. If some area has some very rich people (or very poor people) this difference is likely going to be higher but that's the wrong thing to focus on. What matters is what is the 50% income and the quality of life you can locally afford with it.