ABSTRACT
This chapter investigates how income mobility varies across subgroups of the older population. It provides the principal motivation for the study of income mobility of older people, and discusses the relevant concepts and measures. Mobility is conceptualised in a variety of ways, each of which leads to quite distinct measures of income mobility for the older population. Benefit income is more often stable, and the income mobility observed in this component is more often upward income mobility. Special care was needed to ensure that the concept of income mobility was operationalised in a manner that was methodologically rigorous and realistic from the older people's perspective. Analogous measures can be applied to capture longitudinal variability of individual income. More onerous is the task of quantifying mobility. Transition matrices are defined using the concept of relative as well as absolute mobility, whereas the income trajectories are defined on the basis of absolute concepts of income mobility only.
