Michael Sobel, University of Arizona

Some Log-Linear and Log-Nonlinear Models for Ordinal Scales with Midpoints, with an Application to Public Opinion on the Environment

Friday, May 2 at 12:30pm in Smith 120

Ordinal responses with a middle category are widely used in public opinion studies, psychology, medicine, computed tomography and other fields. The usual models in the statistical literature for ordinal response variables treat the case where the scale has a natural middle category no differently from the case where the scale does not have a middle category. I propose new models for the analysis of ordinal response scales with middle categories, applying these to data collected in 1993-1994 on American opinion toward the balance between environmental quality and economic prosperity. Some of the models should also be useful when the scale does not have a natural middle category. The models are easily used to address issues of concern in empirical work, for example, stochastic ordering among covariate classes and asymmetry about the middle category.