Tying Up the Loose Ends in Simple Correspondence Analysis

Abstract:     
Although correspondence analysis is now widely available in statistical software packages and applied in a variety of contexts, notably the social and environmental sciences, there are still some misconceptions about this method as well as unresolved issues which remain controversial to this day. In this paper we hope to settle these matters, namely (i) the way CA measures variance in a two-way table and how to compare variances between tables of different sizes, (ii) the influence, or rather lack of influence, of outliers in the usual CA maps, (iii) the scaling issue and the biplot interpretation of maps,(iv) whether or not to rotate a solution, and (v) statistical significance of results.

Number of Pages in PDF File: 37

Keywords: Biplot, bootstrapping, canonical correlation, chi-square distance, confidence, ellipse, contingency table, convex hull, correspondence analysis, inertia, randomization test, rotation, singular value

JEL Classification: C19, C88

working papers series