On the Implication of Perception of Genetic Risk and Investment in Health Capital

Objectives: Behavioral scientists have struggled to explain the persistence of poor health choices especially among individuals who, due to poor genes, seemingly have the most to gain from choosing behaviors that mitigate the effects of genetic factors on health capital. The objective of this paper is to explain such behavior in the context of the health capital model laid out by Grossman in 1972. In particular, it is argued that rather than the usual treatment of genetic factors as affecting initial health capital, it is argued that genetic factors affect the individual’s perception of the rate of depreciation of health capital. Grossman argues that the rate of deprecation of health capital increases with age, which eventually reduces the amount of health capital demanded. It is conceivable that individuals who perceive vulnerability to certain health conditions expect to face an exponential rate of increase in the rate of depreciation of health capital, which will accelerate the speed with which they reach the death stock (H_min). The implication is that the amount of health capital demanded falls over time and investment in health capital may also fall over time, even to zero.

 Data and Methods:  An illustration of the hypothesis outlined above is provided using data from a small but intensive sample of workers in a rural town in the southeastern United States. Approximately 400 workers from four companies were targeted for participation in a workplace wellness program. All workers have health insurance. Of the 400 targeted workers only 91 were willing to participate. These 91 workers completed a questionnaire asking for details of family history of chronic diseases (heart disease, stroke, cancer, diabetes, high blood pressure, high cholesterol), whether they believe each of these diseases “run” in their family, and participation in certain health behaviors (smoking, alcohol consumption and exercise, seeking health information). Participants were also asked to estimate their BMI category (normal weight, overweight and obese). In addition, each participant was weighed and measured (height, waist and hip, and circumference of upper arm) and blood pressure checked twice.

Expected Results: We expect to show that individuals who believe high cholesterol and high blood pressure run in their family have different investment in health capital than individuals who believe stroke, cancer and diabetes run in their family. We measure investment in health capital using participation in exercise and smoking, and BMI category. (Given the wealth of published information on the health risks associated with high excess body weight, BMI category must be considered part of the individual’s long term investment strategy.) This difference in investment in health capital can be explained if individuals perceive that stroke, cancer and diabetes cause more rapid depreciation of health capital than high cholesterol and high blood pressure.