Last week I posted some crude calculations on how much states import and export various foods from other U.S. states. Sandy Dall'erba from the University of Illinois alerted me to a dataset that gets at this question in a different way through records of interstate shipments (the FAF database from the Bureau of Transportation). Sandy graciously agreed to let me share this figure he created based on these data.
You can read more about Sandy's work with Zhanglaing Chen here or contact Sandy to get a copy of their working paper "Drought, Interstate Trade and Agricultural Profit: Theory and Evidence" presented this year at the North American Regional Science Conference in Vancouver.