Right-left asymmetry in an eigenvector ranking procedure

A suggestion for the prioritization of alternatives using the Perron-Frobenius right eigenvector of a pairwise comparison matrix has recently been made by T. Saaty. We note that use of the left eigenvectors is equally justified (as long as order is reversed). The purpose of this note is to point out that the resultant prioritizations may disagree even when the comparisons are “nearly consistent.”