Some areas are going to be more dense with upper middle class than other. Some people are going to earn more than others. If San Fran hadn't stopped itself from growing, it would have plenty of room for both the upper and lower middle class, like Toronto does. Economics isn't a war between the haves and the have nots, it's a manner to allocate resources. We should be focused on increasing production and efficiency, not on making sure everyone in life is equal. That will never happen.