Conceptualizes aging as the dynamic process of cohorts moving through the life course in historical time. Provides a strategy for developing research on life course structure, age differences between cohorts, and how and why aging is experienced differentially by various segments of a cohort. (SNR)

Develops a theoretical framework that explicates factors determining the level of care given and care received by cohorts moving through different stages of later life. Specifies four proximate determinants of caregiving and three proximate determinants of care receiving. Focuses on social changes that could reduce the burden of aging. (RJM)