Life Expectancy and Demographics
Life expectancy, in general terms means, the average number of years that a human being is expected to live for. At any cost, life expectancy should not be confused with the mortality rate. Unlike mortality rate, life expectancy is the expected number of years of life for a person.
Life expectancy is only an average estimated number; a person may die much before or live much beyond his expected time of survival. According to this report, life expectancy, in the statistical sense, is the expected number of years of life remaining at a given age. It is denoted by , which means the average number of subsequent years of life for someone now aged X, according to a particular mortality experience. The term life expectancy is not only used for human population, but also used for the plant and animal world, for ecological evolution. However, here we will be discussing life expectancy in terms of human population.
Life expectancy is dependent on many factors and varies from person to person. Following are some of the factors that affect the life expectancy count.
- Time: Life expectancy varies with different historical periods.
- Region: Geographical regions and climate etc. are highly significant in terms of calculating the average life expectancy.
- Economic circumstances
Studies have shown that different historical eras have had different average count of life expectancy. Most importantly, due to the evolution of technology and massive development in the field of science and medicine, the life expectancy of a particular person and even, infant mortality rates have massively increased in the present century as compared to earlier.
As mentioned on this page, the World Health Organization has observed a healthy life expectancy among the people in the last thirty years, and as a result, the number of centenarians has also drastically increased in developed countries, at approximately 5.5% per year, which means doubling the centenarian population every 13 years, pushing it from some 455,000 in 2009 to 4.1 million in 2050.
As per a table given in the above mentioned site, it can be seen that life expectancy has drastically increased from Upper Paleolithic era to the modern 21st century world. As many of the analysts say, it is mostly due to cultural evolution rather than genetic evolution. Also, because an individual, as he grows up, survives the higher mortality rate associated with childhood, life expectancy of a person increases more and more as he or she grows up.
Geographical and regional variation puts an impact on the life expectancy of the population. This is mostly due to the difference in health, diet, climate and environmental calamities of particular region. For example, in a region which is highly prone to dire environmental crisis, the life expectancy rate of the population immediately goes down.
Also, regions like Africa have very low life expectancy rate, due to the vulnerability to deadly diseases in the area. Therefore, quite evidently, during the last fifty years, where highly developed countries have been enjoying a higher life expectancy rates, the scene has not been the same for the African continent. As given in this article, in a survey done by WHO in 2013, of countries for their life expectancy, Monaco, Japan , Andorra and Singapore are some of the countries that have topped the list of life expectancy, with a life expectancy rate of 87.2, 84.6, 84.2 and 84 repectively.
There is always a major difference in the rate of male and female life expectancy due to obvious biological reasons. According to this page, women mostly have a lower rate of life expectancy than men. This is mainly due to the whole process of childbirth and the complications linked with it.
At the same time, in most of the aged groups, it is seen that 90% of the population is female. In the classical age too, men were most likely to face an early death due to the consumption of more drugs, alcohol and tobacco compared to the amount that a female will.
Economic circumstance is an obvious cause that affects life expectancy rate. For example, the mortality rate automatically goes down for wealthier countries than for poorer countries. This is because of the obvious fact that wealthy countries have medical facilities and most importantly, better living conditions that makes the lifestyle easy and favorable for its citizens; which, however is not the case with the third world countries.
According to a study mentioned in this article, the wealthier the lifestyle is, the more the rate of the life expectancy both in the case of male and female.
In today’s world of modernity, talking about race as a determinant factor of life expectancy is actually somewhat shocking. But the truth is, life expectancy is actually highly dependent on the race of the population. Many studies have shown how the black population in the US has a much lower standard of living than the White population, and thereby the former has a much lower rate of life expectancy than the latter.
As mentioned in this page, life expectancy for black males was 4.7 years lower than that of white males and this difference was due to higher death rates for black males from heart disease, homicide, cancer, stroke etc,. For a detailed account of life expectancy on the basis of gender and race refer to this article.