[neffy]

If one was to be brutally fair about this, those so called "GDP" draining states, otherwise known as the Farmers who not only feed the USA but also sell half of their crop abroad, would be far better off as separate countries, with their own currencies and local banks to provide lending, rather than being the source of financial flows that prop up places like New York city.

And in this putative local warlord future that you're imagining for the US, I rather suspect ownership of food production will matter quite a lot.

[zelon88]

I'll be honest I never thought of it that way but it's a good point. Food production is the main export of the states I had in mind in my original post. However, food production shouldn't be counted as a "value added" (arguably, since they don't export enough outside US borders to turn a standalone profit) to the American economy. In the same way that Quality Control is not considered "value added" to a factory, but it is still very much a required part of manufacturing.

However, Japan has very few arable farming areas and get something like 70% (I made that up) of their food from the ocean. In the absence of American farmlands, I'd wager that fisheries would be able to sustain urban coastal areas almost indefinitely.

In all the Mad Maxx/Book of Eli style movies, the characters are almost always inland, trying to get to a populated coastal area where survival is more practical.