Introduction

While the economic base model has been the object of continuing, almost relentless criticism, it possesses one major characteristic of considerable importance, namely, the ability to trace the direction of causality without resort to complex mathematical manipulation. Of course, such transparency of action-through-to-reaction is bought at a very high price – the litany of problems and limitations is well known and will not be repeated here. However, in recent years, tractability in model development has been lost in the rush to produce more complex systems; while our current stable of regional and interregional models is far more elegant than two decades ago, the inability to provide insights into the finer structure of some of these systems has reduced them, for all intents and purposes, to black boxes. The objective of this chapter is not to provide a call for a return to the parsimony of the past, but rather to incorporate, in the present models that favour system-wide visions of economic structure, some of the flavour of transparency that accompanied the simpler expressions of structural interrelationships in earlier, regional models.

This chapter draws on a four-region interregional social accounting system (BIRSAM) developed for Bangladesh (see Jahan and Hewings, 1990) and proceeds to examine several alternative decompositions of this system to provide insights into the way changes move between sectors and across regions.