Stereotypes would have us believe that it’s a direct contest between the olive-oil-drenched Mediterranean and seaweed-wrapped Japan for the honor of the world’s oldest population, although new data reveals that wrinkly sundried tomatoes and fishy greens may not provide the keys to old age after all. Instead, it is the Australians and the Swiss, with their all-round high standard of living, that are enjoying the longest golden years.
Appearing in the journal Population Studies, the new research was conducted with the intention of devising a more accurate model for analyzing mortality rates than those currently used to generate official life expectancy figures.
At present, these figures are typically calculated using what are known as period life expectancies. This involves finding the average age of death for people in a particular country at a given time, and then applying this life expectancy to all members of the population. So, for example, if the average age of death is 79, then it is said that everyone younger than 79 has not yet reached their life expectancy, while all octogenarians have exceeded it.
However, this fails to take into account the fact that people born in different years will have lived through different events and situations, all of which are likely to affect their health and therefore their life expectancy. This means that a person who is currently 55 shouldn’t really expect to live to the same age as someone who is currently 25.
For this reason, mortality rates are sometimes calculated using cohort life expectancies, which involve finding the average age of death for people born in a particular year. While this may give a more accurate estimation for a person’s actual old-age prospects, cohort life expectancies are rarely used as they can only be obtained once every member of a particular cohort has already died, rendering them useless for predicting life expectancies for the living.
However, by analyzing cohort life expectancies for every year since 1950 in 15 different countries, researchers were able to come up with a model for predicting future cohort life expectancies.
Based on their calculations, the study authors claim that Australian men have a higher life expectancy than any other male group, living to 74.13 years, while Swiss women are the most enduring females, reaching 79.03 years old.
Swedish men are forecast to be the second most permanent group of males, living to 74.02 years, while Australian women marginally trail the Swiss, living to 78.79 years old.
Describing the significance of this approach, study co-author Collin Payne said in a statement that “our measure takes the life course into account, including mortality rates from 50, 60, or 70 years ago… What matters is we're comparing a group of people who were born in the same year, and so have experienced similar conditions throughout their life.”