it's called classical for commerce and the history of the policy and one of the points that doug erwin makes is that they are unstable for about a hundred years up until about 1980. if you go back and want to know where the industrial midwest was, in northwest ohio today to make automobiles in marysville big automobiles in marysville up the way from marysville and 18 a.d. it was the producer of steam locomotives much like in the wheat belt people grew crops in the financial services they were very important to trade in the beginning so there was a political geography so every trade agreement was essentially bipartisan and geographically specific so you are a senator from new york it doesn't matter whether democrats, patrick moynihan or democrat, trade was good for new york likewise south carolina you have strom thurmond and senators from south carolina because of the concentration of the payroll in the state of south carolina. now that all changed in three important ways. what happened is because of the information revolution all of a sudden the communication costs long-distance phone