Estimating effects in ordinal dummy variable regression

Abstract

This paper discusses the ordinal dummy variable coding system and its use on categorical data. In this method each originally coded interval-scale parent independent variable is represented by a set of ordinal dummy variables of 1's and 0's designating the various levels of that parent variable. The effect of a specified parent independent variable on a dependent variable is shown to be the weighted sum of the net effects of its representative ordinal dummy variables on the dependent variable, where the weights are the simple regression effects of the ordinal variable on its parent dummy variables. The method is illustrated with some data set.