Directional instability in the eigenvectors of positive reciprocal matrices

This article addresses the issues of rank stability and ‘bilateral’ consistency that arise when a matrix‐based decision analysis procedure is perceived as capable of yielding more than one weighting vector, for example, both a right and component‐wise inverted left eigenvector. Simple directional constraints that characterize both of the above issues are presented. Copyright © 1999 John Wiley & Sons, Ltd.