A Method for Constructing Commodity by Industry Flow Matrices

This paper presents theory and methods 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) social accounting matrices (SAMs) using data derived 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 Transportation Statistics. The estimated interregional SAM is then adjusted to insure the integrity of intra-regional and system-wide accounts. The procedures have been designed with ease of replicability as a goal so that updates and extensions of the database can be generated efficiently and at low cost as new data are released. The resulting US interregional framework describes flows within and among the 51 regions. The method is flexible and will provide a valuable database for a broad range of analyses on regions, interregional relationships, and policy.