Comparing Post-Stratification and Propensity Score Nonresponse Adjustment: Bias Correction and Precision Loss – a Case Study with the Swiss ESS 2012 Data
We will study two nonresponse adjustments for the ESS 2012 survey in Switzerland. The first will be based on socio-demographical variables from the population register from which the sample is drawn. Such paradata are commonly used in post-survey adjustment, as they are often the only data available. But they are known to have low correlations with response propensities and with many key variables. In a second step, data from the nonresponse survey that was conducted shortly after the main ESS 2012 will also be used to construct post-survey adjustment. The nonresponse survey is designed to collect information that correlates highly with the propensity to answer and should lead to an efficient nonresponse adjustment. The expected decrease in bias could sadly be neutralized by the possibly substantial effect on precision of such a weighting scheme. A second shortcoming is that the core of the nonrespondents that did not participate to either survey cannot be corrected for. Our aim is to compare these two methods, assessing the effect on estimates, nonresponse bias and on the precision of these estimates by applying a bootstrapping.