UPPER BOUNDS ON THE SIZES OF INTERREGIONAL FEEDBACKS IN MULTIREGIONAL INPUT-OUTPUT MODELS*

ABSTRACT. Upper bounds are presented for a measure of the overall percentage error caused in a multiregional input-output model when interregional feedback effects are ignored. This error figure is thus a measure of the magnitude of interregional linkages. The upper bounds are expressed as a function of the levels of self-sufficiency in the regions in the model and of the norms of the regional technical coefficients matrices. Experimental results are presented for a variety of examples that are thought to reflect real-world situations, and it is clear that in many cases the upper bound (and hence the error) is extremely small. The implication is that single-region input-output models may be adequate for a variety of questions.