Family health effects: complements or substitutes

Genetic endowments play a fundamental role in the production of health. At birth individuals have different capacities to be healthy, largely due to genetic dispositions. Whether or not individuals realize this health depends on their choice of health behaviours. Previous research has linked negative factors beyond the individual's control, which include genetic endowments, to both poor health and poor health behaviours. The health economics literature proposes that behaviours and genetic (or family health) endowments can be either substitutes or complements in the production of health. The goal of this paper is to investigate the behavioural consequences of changes in knowledge about one's genetic endowment. Using two waves of the National Health and Nutrition Examination Survey I Epidemiologic Followup Study, I find that for smokers, smoking intensity substitutes for newly diagnosed smoking-related family cancers, while smoking intensity is complementary to newly diagnosed non-smoking-related family cancers. I find no evidence for the hypothesized relationships with respect to alcohol consumption among drinkers. These results have implications for the growing field of genetic testing and test development. These results also reinforce current practices of ascertaining family health histories in the context of medical history taking.