Understanding the correlation between Alzheimer’s Disease polygenic risk, wealth, and the composition of wealth holdings

Abstract

We investigate how the genetic risk of developing Alzheimer’s Disease (AD) relates to saving behavior. Using nationally representative data from the 1996–2014 Health and Retirement Study (HRS), we find that genetic predisposition for AD correlates with, but is not causally related to how older individuals’ hold wealth in different asset types. People with a higher AD polygenic risk score (PGS) hold roughly 20 per cent less wealth in IRAs and contribute about 24 percent less to IRAs between survey periods. We hypothesize that people with a high risk of AD choose different portfolios: (i) because they know their genetic risk of developing AD from parental history, (ii) because they have the lower cognitive capacity, and (iii) because they indirectly learn about their genetic predisposition for AD as they age. Our extended model results show that the first two hypotheses do not account for the observed correlation. Consistent with the third hypothesis, the interaction between age and the AD PGS accounts for the correlation between genetic traits and asset holdings. Our findings have far-reaching implications for researchers using genetic data: when indirect learning about own predispositions is possible, correlations between genes and choices must be interpreted with caution.