It is well known that older people’s response behavior is different compared to other age groups. These differences are not only related to distinct attitudes and values of this specific age group but also to diminishing cognitive skills and memory capacity that is associated with aging. As a consequence, item non-response and different types of response sets are, among others, more common since older people experience more difficulties handling question and answer sets. Most research in this field is done by cross-sectional data which is accompanied by the problem that examined groups are not only differentiated by age but also by education, attitudes, interest towards the topic and other indicators that influence the quality of data. Based on longitudinal data such as the German Socio-Economic Panel Study (GSOEP), it is be possible to look at a cohort that has reached a high age and compare their answer patterns of certain sets of unchanged variables over the last 20 years. The advantage of this approach is that a decrease of data quality can be interpreted as an age-related response behavior of the elderly.