Exchanging regional input-output coefficients: a reply and further comments.

Some issues raised by Thumann in response to an earlier article by Hewings are addressed in the context of discovering efficient ways of exchanging input-output coefficients. Several extensions to the RAS procedure are reviewed; in particular, attention is focused on the issue of fixing certain coefficients prior to the application of biproportional adjustment algorithms. An appendix contains a discussion of measures which minimize the distance between two matrices. - Authors G. J. D. Hewings, Department of Geography, University of Illinois, Urbana, Illinois 61801, USA. B. N. Janson, Department of Civil Engineering, University of Illinois, Urbana, Illinois 61801, USA.