Population Aging And Human Life Expectancy - 1160 Words

In the present days, the world is experiencing the transition in its population, the total number of people aged 65 and more has gradually become larger. This transition is called population aging. Population aging refers to a trend that the proportion of people aged 65 and more is expanding in an area. Population aging can be measured by the ratio between the total number of people who are 65 years old and older than 65-year-old and the total population in a certain district. In the United States, the situation of population aging is more severe than that in the past. The decrease in both mortality and fertility and the advanced medical technology that helps in expanding human’s life expectancy can be main reasons for this†¦show more content†¦According to Siegel’s article based on the discussion of the social security system and the age distribution of the population, Siegel thinks that there is a strong relationship between the social security system and the age distribution of the population and the elderly aged dependency ratio can be the proper measure to reflect the link between elderly people and working age population. The elderly dependency ratio is based on past trends of mortality, fertility and net migration to project population in the future. This measure presents constant growing in the population; especially, it gives relatively possible population number for the next two decades. However, elderly aged dependency ratio is not a reliable measure when it is used to project the future population more than two decades. For example, individuals in the U.S. have become reluctant to have kids, as the opportunity cost of having a child is considerably high while a person’s income after tax and other fees is comparatively low. On the other side, with the improvement in medical technology and health care system, the mortality rate has decreased. Human’s life expectancy has changed over past several decades. It is stat ed in Siegel’s article â€Å"Between 1935, †¦ †¦, and 1997, life expectancy at birth rose from 59.9 years to 73.6 years for men and from 63.9 years to 79.4 years for women.† This demonstrates a dramatic change in human’s life