Implementing point-symmetry models for square contingency tables having ordered categories in SAS

In this paper, the class of point-symmetry models in a square contingency table discussed in (Tomizawa, 1985; 1986a; 1986b) are implemented in SAS by employing the non-standard log-linear model approach discussed in (von Eye and Spiel, 1996), and (Lawal, 2001). This approach is simpler than earlier implementation of these models as it unifies the approaches in various papers by Tomizawa. The implementation of these models require the generation of factor and regression variables whose entries derivation are explained in the text. The models are fitted using SAS PROC GENMOD.