It seems to me that, for cities that border other states, it is almost always the case that the suburb (or, really, smaller city in the metro area) in the worst shape lies across a state line.
For instance:
Chicago -> Gary
St. Louis -> East St. Louis
Philadelphia -> Camden
New York -> Newark
Maybe Memphis-> West Memphis, KC -> KCK are examples as well? I don't know enough about Cincinnati, Charlotte, or Portland to answer for them. Omaha or Louisville might be too small of a metro area to have a really bad suburb?
Anyway, if this is true, why might it be?
Conjecture: The wealthiest persons tend to live in the major cities, and there are also typically more cultural institutions and universities. The state line cuts off expansion of the cities proper, so the cross-state areas may be close, but are separate. There may not be jobs created in these areas. Housing is cheaper and there is less resistance to Blacks moving in, or Whites moving further out.
