What is life expectancy ?
In demography, life expectancy is a statistical concept that indicates the mean, or mathematical expectation of the remaining life of an individual in the particular group. For non-human organisms, the term service life is often used to indicate the average length of the life of a particular species.
The life is strongly dependent on the criteria used to select the group. In countries with high infant mortality, life expectancy at birth very sensitive to the mortality rate in the first year of life. In these cases, a different criterion such as the life expectancy could be used at the age of 10 years in order to eliminate the effects of infant mortality and to reveal the effects of other causes of death. Nevertheless, it is usually the specified life expectancy at birth. To calculate which assumes one that the current mortality rates continue through the life of the hypothetical newborns constant.
The age at which most people die is generally much higher than the arithmetic life. Around 1860, life expectancy in the Netherlands was still on the shockingly low level of 37 years. Nevertheless it was the age when most people still died even 73 years. The current life expectancy is around 78 years, while most people die at the age of 85 years. The difference is closely related to child mortality, which was significantly higher in the 1860s than today.
Life and human history
Life expectancy in the course of the last centuries of human history has increased dramatically. This improvement is largely the result of improved hygiene (sanitation and clean drinking water), availability of good food, living conditions (heating), peace and medicine. In the latter yielded particularly the invention of antibiotics a major role. The greatest improvements have been made in the richest parts of the world but is now spreading the same effects in other parts of the world as to improve their economies and infrastructure. Life expectancy has risen sharply in the 20th century, especially in developed nations. Life expectancy at birth in the United States in 1901 was 49 years. At the end of the century it was 77 years, an increase of more than 50%. Such increases have also occurred in other parts of the world. Life expectancy in India and the PRC was around 40 years in the middle of the century. Around the turn of the century, this had increased to around 63 years. These increases were largely attributable to the eradication and control of many infectious diseases and to advances in agricultural technology (such as chemical fertilizers).
The main exception to this general pattern of improvement has been in those countries most affected by AIDS, mainly in southern Africa. There are far too significant decreases in life expectancy due to the diseases that have done in recent years introduced.
Another exception is Russia and other former republics of the Soviet Union after the collapse of the Soviet Union. Life expectancy for men dropped to 59.9 years (below the official retirement age) of women to 72.43 years (1999).
In recent years, the obesity-correlated diseases have become a major public health issue in many countries. The rise in obesity is thought to be a potential health risk due to rising risks of cancer, heart disease and diabetes.
The entire human history was the largest part of the increase in life expectancy as a result of the prevention of early death. However, many scientists believe that this will continue in the future. Some scientists believe that further progress in medical science, life expectancy may increase even further.
Differences in life expectancy in the world
Worldwide, there are major differences in life expectancy, which are usually caused by differences in public health, medicine and food from country to country. Average life expectancy and prove fertility (number of children per woman) negatively associated: the longer life expectancy, the less children. A comparison of all countries and regions shows that especially the increased prosperity and the extended life (and not the culture or religion) is related to the decreased fertility.
There are also differences between groups within the same country. For example, in the U.S. were there in the early 20th century, very large differences in life expectancy between people of different races. Nowadays, these differences are smaller. There are significant differences in life expectancy between men and women in developed countries. Women are usually older. These differences between the sexes has narrowed in recent years, as the life expectancy of men is rising faster than that of women.
The harmful effects of habits such as tobacco and other addictions also provide a significant difference in life expectancy. Smoking is the main reason why in Europe the average life expectancy of men is lower than that of women.
Another important related to life is with the profession. People in occupations requiring higher education is needed, have a higher life expectancy. One part is due to the working conditions. Working with asbestos mines and provides a lower life expectancy. Takes in developed countries through improved safety at work this proportion deviate. Another part is due to a correlation between the choice of the profession and the choice of lifestyle. Genetic predisposition plays a smaller role.
Life expectancy and retirement
In many Western countries, the retirement age of 65 for discussion. The argument that evidence as they often raise the retirement age, is that the average age is getting higher, which would justify a later retirement age. But the problem here is that calculated life expectancy at birth ('normal' life expectancy), and not from the retirement age, the remaining life expectancy. Life expectancy is rising, but the remaining life expectancy rose initially yet. This was for example by decreasing infant mortality. As long as the age at death of a group increases, while people still die before retirement, there is no argument for raising the retirement age. In the Netherlands, the last 50 years of the last century, life expectancy, but the remaining life expectancy at 65 increased, especially for men, not significant. In 1960, the life expectancy of 65 year old men still 13.9 years, compared to 15.4 years in 2006. After 2000, however, also came to the remaining life expectancy of 65 were increased significantly. According to calculations by CBS in 2011, 63% of men will reach the age of 80 years. For women, the percentage is 75%.
Although life expectancy in the Netherlands increased, the risk to die for people with advanced age (90 years and older) in the last 20 years to clear weather; where a lady of 98 years around 1980 had a chance of more than 71% to reach the age of 99 years, the chance is now down to 66%. Increased longevity can be attributed to declining infant mortality and the last period especially the declining mortality in middle age. As a result, there are still significantly more people of old age, despite the increased mortality for this group.
Based on figures from Statistics Netherlands 2008, yet the Netherlands showed a strong increase in perceived life (an increase of 1.4 months per year, with particularly favorable developments in the fight against cardiovascular disease and reduced mortality high ages), the Actuarial Association announced in December 2009 in 2010 to come up with new mortality tables. De Nederlandsche Bank, supervisor of the pension funds, however, was immediately know immediately (thus at 31 December 2009), account should be taken of the new insights. Many pension had on the basis of the tables published in 2010 still further increase their facilities.
Two years later, in September 2012, confirms the new forecast of the Actuarial Society again that women and men live longer than previous forecasts indicate. The life expectancy of men and women at birth increased from 79.5 years to 83.1 years respectively. And (important in old age: effect about 1%), the remaining life expectancy of 65 years takes men and women in 2012 to 18.1 years to 21.1 years respectively. The difference in life expectancy between men and women has narrowed again. It should be noted that rather than the upper limit of the beneficial increasing age to be achieved, but that the part of the people that achieves a high age, rises. In short, more people are getting old.