People are indeed living longer, but they are also aging more slowly. A study in the journal Science published on Friday offers considerable hope that the combination of greater longevity and low birth rates will not, after all, impose an overwhelming burden of health-care and pension costs on the world's developed economies.
The upward pressure of health costs is unmistakable, taking a rising proportion of government budgets and overall spending, but other factors of supply, demand and public policy may turn out to be much more important in this respect than increased life expectancies.
Warren Sanderson, an American economist and historian, and Sergei Scherbov, a systems scientist and demographer in Austria, point out in their paper "Remeasuring Aging" that the United Nations and the Organization for Economic Co-operation and Development and other institutions have made projections based on "the old-age dependency ratio," which compares the number of people aged 65 or more with the number of adults of working age. The built-in assumption is that the ability to earn income ceases on one's 65th birthday, which is becoming less and less true. Moreover, the heaviest health-care costs tend to be in the last few years of one's life - which are getting farther away from 65.
The old-age dependency ratio has had the convenience of simplicity and consistency across countries with differing cultures and disability rates. But consistent measures of disability - not reliant on self-evaluation - have emerged. Professor Sanderson and Dr. Scherbov propose instead an "adult disability dependency ratio": the mathematical relationship between adults with disabilities and all adults. They then compare the OADR and ADDR for 2005-10 and for two future five-year periods. With the OADR, dependency is forecast to more or less double in 27 countries. With the ADDR, there is only a slight increase.
In Canada, the authors project a change from an ADDR of 0.09 in 2005-10 to 0.11 in 2045-50, which would be quite manageable. These figures happen to be the same for France - where President Nicolas Sarkozy is encountering vehement opposition to a small rise of the retirement age from 60 to 62. That is a reminder that public and private pension costs present institutional problems different from those of health care.
Longer life has, and will have, manifold consequences, but the apocalyptic "grey dawn" that some fear is unlikely to take the shape of a fiscal meltdown over health care.