Attrition in the Austrian generations and gender survey: is there a bias by fertility relevant aspects?

Isabella Buber-Ennser, Wittgenstein Centre (IIASA, VID/ÖAW, WU)

In longitudinal research, the loss of sample members between waves is a possible source of bias. It is therefore crucial to analyse attrition. The current paper analyses attrition in a longitudinal study on family and fertility, by distinguishing between attrition due to non-contact and attrition due to cooperation. Based on the first two waves of the Austrian Generations and Gender Survey, the two components of attrition are studied separately by using bivariate as well as multivariate methods. Moreover, overall dropout – the combination of both components – is analysed. Apart from various socio-economic characteristics and data collection information, the study focuses on fertility relevant variables such as fecundity, fertility intentions, sexual orientation and traditional attitudes. Fecundity, fertility intentions and homosexual relationship are associated with higher attrition due to cooperation in bivariate analyses but have no explanatory power in the multivariate model. Pregnancy and traditional attitudes towards marriage are associated with significantly lower attrition due to cooperation in the multivariate context. Overall dropout is significantly lower among persons with traditional attitudes towards marriage only. Moreover, various individual and regional characteristics are significantly associated with dropout, with differences between attrition due to non-contact und attrition due to cooperation. Detailed insights in attrition are important when using longitudinal data and interpreting results. Analyses based on the first two waves of the Austrian Generations and Gender survey have to take into consideration a bias towards family oriented persons as well as lower educated respondents and persons with migration background.