This last measure is really interesting. How do borders work though?
I am in NW Washington, but only about 50 miles from Vancouver so technically under this metric I'd be counted in the Vancouver CSA? But even though Vancouver is technically the closest city, I think most of us up here would be much more likely to consider ourselves under the "Seattle sphere of influence."
Although, wow.... looking at the map you can practically see the outline of "where the agglomeration would have been" if there hadn't been a border.
