The life expectancy of people in the "G-7" (Group of 7) industrialized nations -- Canada, France, Germany, Italy, Japan, the United Kingdom, and the United States -- may be greater than previously thought, according to a new study. A new mortality forecast suggests that by 2050, the populations in these countries may be living from 1.3 years (UK) to 8 years (Japan) longer than official estimates now predict.
The assessment, by Shripad Tuljapurkar, Ph.D., Nan Li, Ph.D., and Carl Boe, Ph.D., at Mountain View Research, Los Altos, CA, appears in the June 15, 2000, issue of the journal Nature. The work was supported by the National Institute on Aging (NIA).
It is no surprise to demographers and officials that the population is aging; in the U.S., the coming of age of the baby boomers has been anticipated for quite some time, with the first "boomer" turning 65 in 2011. But Tuljapurkar's report suggests that mortality rates in G-7 countries will continue their historical decline, as science continues to alter the face of medicine and public health. With lower death rates, he says, population aging in these countries could be greater than expected by the middle of the 21st century.
"Studies such as these are important in helping to forecast demographic shifts," says Richard M. Suzman, Ph.D., Associate Director of the NIA for Behavioral and Social Research. "Being able to predict how these populations will age has enormous implications for the planning and provision of services and support. Small increases in life expectancy translate into large increases in the population."
The Tuljapurkar study is based on newer demographic models looking at 5 decades of mortality data for these countries. It found that mortality at all ages in every country has declined at a steady, exponential rate for the past 50 years. This surprisingly general pattern of long-term linear decline in mortality is expected to continue, Tuljapurkar believes, as resources invested in improving public health continue to show some effectiveness against mortality, even amid a growing complexity in the causes of death.
The analysis presents median estimates of life expectancy in 2050 in each country, contrasting them with current government estimates, as follows:
The authors point out that these differences in forecasted life expectancy influence the ratio of the population over 65 to the population ages 20 though 64. This ratio, sometimes referred to as the "dependency ratio," is often examined by demographers and planners because it viewed as an important concept for planning retirement systems and health care programs. In 2050, the scientists figure, these ratios would be higher by between 6 percent (UK) and 40 percent (Japan), suggesting that programs for old-age support, which may be based on official life expectancy estimates, may need to be re-examined.
The NIA, one of 25 institutes and centers comprising the National Institutes of Health (NIH), leads the federal effort supporting and conducting research on aging and age-related conditions and issues of older people and their families. Its Office of the Demography of Aging has supported a number of national studies and analyses on population aging, health, and retirement.