Expenses don't change with city size with a few exceptions. Housing being the only one they look at, which I think is fair. With housing costs removed they say

Expenses don't change with city size with a few exceptions. Housing being the only one they look at, which I think is fair. With housing costs removed they say - "The poorest two deciles in bigger cities make about the same income as their counterparts in smaller cities" Which does match the title. I think there are a few obvious problems with this. But as a paper it's a good start. I object to the strongly worded title, but it's not wrong from the paper.