Method for Constructing Commodity by Industry Flow Matrices

This paper describes the method used to construct an interregional Commodity by Industry Flow matrix for the United States. The interregional flow matrix method involves the construction of single-state (and DC) SAMs using data from IMPLAN. Once complete, the interregional flows connecting states are estimated using a method based on the Commodity Flow Survey data published by the Bureau of Transportations Statistics. The estimated interregional SAM is then adjusted to insure the integrity of intraregional and system-wide accounts. The procedures have been designed with the goal of ease of replicability, so that updates and extensions of the database can be generated efficiently and at much lower cost as new data are released. The resulting US interregional framework describes flows within and among the 50 states and the District of Colombia, and will provide a valuable database for a broad range of analysis on regions, interregional relationships and policy research.