Research Paper HEDG Working Papers 05/05
Health-related non-response in the the BHPS and ECHP: using inverse probability weighted estimators in nonlinear models
01 Jun 2005
This paper considers health-related non-response in the first eleven waves of the British Household Panel Survey (BHPS) and the full eight waves of the European Community Household Panel (ECHP) and explores its consequences for dynamic models of the association between socioeconomic status and self-assessed health (SAH). To address this issue we describe the pattern of health-related non-response revealed by the BHPS and ECHP data. We both test and correct for non-response in empirical models of the impact of socioeconomic status on self-assessed health. Descriptive evidence shows that there is health-related non-response in the data, with those in very poor initial health more likely to drop out, and variable addition tests provide evidence of non-response bias in the panel data models of SAH. Nevertheless a comparison of estimates - based on the balanced sample, the unbalanced sample and corrected for non-response using inverse probability weights (IPW) - shows that, on the whole, there are not substantive differences in the average partial effects (APE) of the variables of interest. The main differences are between unweighted and IPW-2 weighted estimates for the APE of income and education in those countries that have fewer than eight waves of data. Similar findings have been reported concerning the limited influence of non-response bias in models of various labour market outcomes; we discuss possible explanations for our results.