The precious and the precocious: understanding cumulative disadvantage and cumulative advantage over the life course.

The explanation of increasing heterogeneity and inequality within aging cohorts is a central concern of the life-course perspective and common ground for demographers, economists, historians, sociologists, and psychologists alike. Income and wealth inequality among the aged is one area of shared interest where cross-disciplinary fertilization is occurring. While indices of aged economic inequality applied across different data sets replicate the level of inequality among the elderly, theoretical and methodological concerns are focused more and more on identifying and specifying the long-term interactions between institutional and life-course processes producing this outcome. Institutional mechanisms incorporated in opportunity structures such as labor markets and pensions stratify the availability of resources and rewards, and they interact with life-course processes related to labor force history and job mobility to produce complex patterns of cumulative advantage and cumulative disadvantage. However, the examination of long-term mechanisms of stratification requires finer-grained observations of work, employer, and pension histories than current data-collection strategies afford. Two biases--the steady worker bias and the one pension bias--are inherent in most longitudinal data bases and hamper progress in our understanding of the production of aged inequality.