Inter-Cohort Trends in Age-Specific Health Inequalities: A Test of the Theory of “Fundamental Causes”

John R. Warren, University of Minnesota
Elaine Hernandez, University of Minnesota
Krista N. Jenkins, University of Pennsylvania

In a series of articles Link, Phelan and colleagues (eg, Link and Phelan 1995) argue that “social factors such as socioeconomic status … are likely ‘fundamental causes’ of disease that, because they embody access to important resources, affect multiple disease outcomes through multiple mechanisms, and consequently maintain an association with disease even when intervening mechanisms change.” Implicit in this argument is an empirical hypothesis: that the association between socioeconomic status and health has remained constant (or increased) across birth cohorts and over time. In this paper we discuss conceptual and practical problems inherent in testing this hypothesis. Briefly, to test this hypothesis it is necessary (for practical reasons) to employ a measure of socioeconomic status that does not change with age and (for theoretical reasons) that carries the same conceptual meaning over historical time. We conclude by using data from a variety of sources to offer evidence regarding this hypothesis.