Some Relationships between T-Accounts, Input-Output Tables and Social Accounting Matrices

Some relationships between the T-accounting format for presenting commodity balances; input-output (IO) tables; and social accounting matrices are discussed in this paper. The starting point is to recognize that IO tables do not contain all the information that is needed to complete a social accounting matrix (SAM), or, therefore, for the modelling of phenomena that depend on having a fully articulated SAM, such as the interdependence of the distribution of income and the structure of production. There is a need, therefore, to establish the character of the extra information that is required and this can be achieved by imposing the requirement that a SAM should be consistent with the basic cash identity that is fundamental to all social accounting. A second agendum is to develop the argument that, while T-accounts can, in principle, provide a database equivalent to that of a SAM, in practice, they are typically found to be an imperfect substitute. It is important, therefore, in designing a database, to go beyond the confines of an (extended) IO system and T-accounts. SAMs provide an appropriate framework for doing so.