Effects of Variables in a Response Propensity Score Model for Survey Data Adjustment: A Simulation Study

On building a model for estimating response propensity score for survey data adjustment, we carried out computer simulations to examine the effects of seven types of variables, each having differing associations with the sample inclusion probability, response probability and study variable, by comparing the respective cases in which the variables are included and excluded by the model. Then the following main results were obtained. The most important variable for the model is the one that is simultaneously associated with the study variable, the sample inclusion probability, and the response probability. The variables which have no association with the study variable should not be included in the response propensity model. These results support the conclusions of Brookhart et al. (2006), who examined propensity score models in their study on estimating treatment effects. Additionally, a small difference was found in comparing the effects of the variable associated with sample inclusion probability and the study variable to those of the variable associated with the response probability and the study vari able.