Health in the US has had a number of impacts on demography over the last few decades. Improvements in health science have caused people to live longer, on average, which creates both pluses and minuses for the economy. Having more people staying healthy and vigorous into their sixties and seventies increases the potential workforce, increases productivity, and increases the return on our investments in human capital. On the other hand, having more people living longer after retirement increases the size of the dependent population, increasing the average burden on those still working.
Unfortunately, the health outlook for the US hasn’t been entirely positive. In some ways, we have become significantly less healthy over the last 40 years, with a growing epidemic of “first-world problems,” including obesity, diabetes, and a multitude of developmental, allergenic, and auto-immune disorders, like Alzheimer’s, autism, asthma, MS, ALS, lupus, and Crohn’s disease, that were quite rare in pre-industrial societies.
As a result, we have seen a disproportionate increase in the number of people who are partially or fully disabled. To the degree that they become disabled early, even in childhood, and still live extended lives, this creates the worst of all demographic effects: fewer workers, more dependents, lower productivity, increased poverty, and higher medical costs.