Life expectancy is the expected (in the statistical sense) number of years of life remaining at a given age.^[1] It is denoted by e_x, which means the average number of subsequent years of life for someone now aged x, according to a particular mortality experience. (In technical literature, this symbol means the average number of complete years of life remaining, ie excluding fractions of a year. The corresponding statistic including fractions of a year, ie the normal meaning of life expectancy, has a symbol with a small circle over the e.) The life expectancy of a group of individuals is heavily dependent on the criteria used to select the group. Life expectancy is usually calculated separately for males and females.

In countries with high infant mortality Infant mortality is defined as the number of infant deaths per 1000 live births. The most common cause worldwide has traditionally been due to dehydration from diarrhea. However, the spreading information about Oral Rehydration Solution (a mixture of salts, sugar, and water) to mothers around the world has decreased the rate of children dying from rates, the life expectancy at birth is highly sensitive to the rate of death in the first few years of life. Another measure such as life expectancy at age 5 (e₅) can be used to exclude the effect of infant mortality to provide a simple measure of overall mortality rates other than in early childhood.

The term life expectancy is most often used in the context of human populations, but is also used in plant or animal ecology Ecology is the scientific study of the distributions, abundance and relations of organisms and their interactions with the environment. Ecology includes the study of plant and animal populations, plant and animal communities and ecosystems. Ecosystems describe the web or network of relations among organisms at different scales of organization^[2]; it is calculated by the analysis of life tables In actuarial science, a life table is a table which shows, for each age, what the probability is that a person of that age will die before their next birthday. From this starting point, a number of statistics can be derived and thus also included in the table: (also known as actuarial tables An actuary is a business professional who deals with the financial impact of risk and uncertainty. Actuaries provide expert assessments of financial security systems, with a focus on their complexity, their mathematics, and their mechanisms). The term life expectancy may also be used in the context of manufactured objects^[3] although the related term shelf life Shelf life is the length of time that food, drink, medicine and other perishable items are given before they are considered unsuitable for sale or consumption. In some regions, a best before, use by or freshness date is required on packaged perishable foods is used for consumer products and the term "mean time to breakdown" (MTTB) is used in engineering literature.

Humans

Humans live on average 39.5 years in Swaziland The Kingdom of Swaziland , sometimes called Ngwane, is a landlocked country in Southern Africa, bordered to the north, south and west by South Africa, and to the east by Mozambique. The nation, as well as its people, are named after the 19th century king Mswati II^[4] and 81 years in Japan Japan is an island country in East Asia. Located in the Pacific Ocean, it lies to the east of the Sea of Japan, China, North Korea, South Korea and Russia, stretching from the Sea of Okhotsk in the north to the East China Sea and Taiwan in the south. The characters that make up Japan's name mean "sun-origin", which is why Japan is (2008 est.), although Japan's recorded life expectancy may have been very slightly increased by counting many infant deaths as stillborn.^[5] The oldest confirmed recorded age for any human is 122 years (see Jeanne Calment Jeanne Louise Calment had the longest confirmed human life span in history, living 122 years and 164 days (44,724 days total). She lived in Arles, France, for her entire life, and outlived both her daughter and grandson. She became especially well known from the age of 113, when the centenary of Vincent van Gogh's visit brought reporters to Arles,). This is referred to as the "maximum life span In animal studies, maximum life span is often taken to be the mean life span of the most long-lived 10% of a given cohort. By another definition, however, maximum life span corresponds to the age at which the oldest known member of a species or experimental group has died. Calculation of the maximum life span in the former sense depends upon", which is the upper boundary of life, the maximum number of years any human is known to have lived.^[6]

Lifespan variation over time

The following information is derived from Encyclopaedia Britannica, 1961 and other sources, and unless otherwise stated represents estimates of the life expectancies of the population The world population is the population of humans on the planet Earth. In 2009, the United Nations estimated the population to reach 7,000,000,000 in 2011; current estimates by the United States Census Bureau put the population at 6,858,200,000 as a whole. In many instances life expectancy varied considerably according to class and gender.

Sometimes, mainly in the past, life expectancy increased during the years of childhood, as the individual survived the high mortality rates then associated with childhood. The life expectancies at birth listed below take account of infant mortality Infant mortality is defined as the number of infant deaths per 1000 live births. The most common cause worldwide has traditionally been due to dehydration from diarrhea. However, the spreading information about Oral Rehydration Solution (a mixture of salts, sugar, and water) to mothers around the world has decreased the rate of children dying from but not pre-natal mortality (miscarriage Miscarriage or spontaneous abortion is the spontaneous end of a pregnancy at a stage where the embryo or fetus is incapable of surviving, generally defined in humans at prior to 24 weeks of gestation. Miscarriage is the most common complication of early pregnancy or abortion Abortion is the termination of a pregnancy by the removal or expulsion from the uterus of a fetus or embryo, resulting in or caused by its death. An abortion can occur spontaneously due to complications during pregnancy or can be induced, in humans and other species. In the context of human pregnancies, an abortion induced to preserve the health).

The average life expectancy in Colonial America The term colonial history of the United States refers to the history from the start of European settlement to the time of independence from Europe, and especially to the history of the thirteen colonies of Britain which declared themselves independent in 1776. Starting in the late 16th century, England, Scotland, France, Sweden, Spain and the was under 25 years in the Virginia colony,^[18] and in New England about 40% of children failed to reach adulthood.^[19] During the Industrial Revolution The Industrial Revolution was a period from the 18th to the 19th century where major changes in agriculture, manufacturing, mining, and transport had a profound effect on the socioeconomic and cultural conditions starting in the United Kingdom, then subsequently spreading throughout Europe, North America, and eventually the world. The onset of the, the life expectancy of children increased dramatically.^[20] The percentage of children born in London London is a leading global city being the world's largest financial centre alongside New York City, and has the largest city GDP in Europe. Central London is home to the headquarters of most of the UK's top 100 listed companies and more than 100 of Europe's 500 largest. London's influence in politics, finance, education, entertainment, media, who died before the age of five decreased from 74.5% in 1730-1749 to 31.8% in 1810-1829.^[21][22]

Public health Public health is "the science and art of preventing disease, prolonging life and promoting health through the organized efforts and informed choices of society, organizations, public and private, communities and individuals." It is concerned with threats to the overall health of a community based on population health analysis. The measures are credited with much of the recent increase in life expectancy. During the 20th century, the average lifespan in the United States increased by more than 30 years, of which 25 years can be attributed to advances in public health.^[23]

In order to assess the quality of these additional years of life, 'healthy life expectancies' have been calculated for the last 30 years. Since 2001, the World Health Organization publishes statistics called Healthy life expectancy (HALE), defined as the average number of years that a person can expect to live in "full health", excluding the years lived in less than full health due to disease and/or injury. Since 2004, Eurostat Eurostat is a Directorate-General of the European Commission located in Luxembourg. Its main responsibilities are to provide the European Union with statistical information at European level and to promote the harmonisation of statistical methods across the Member States of the European Union, candidate countries and EFTA countries. The publishes annual statistics called Healthy Life Years The Healthy Life Years indicator is a European structural indicator computed by Eurostat. It is one of the summary measures of population health, known as health expectancies, composite measures of health that combine mortality and morbidity data to represent overall population health on a single indicator (Robine, 2006, p160-168). HLY measures (HLY) based on reported activity limitations. The United States of America uses similar indicators in the framework of their nationwide health promotion and disease prevention plan "Healthy People 2010 Healthy People 2010, started in January 2000 by the United States Department of Health and Human Services, is a nationwide health promotion and disease prevention plan to be achieved by the year 2010". An increasing number of countries are using health expectancy indicators to monitor the health of their population.

Regional variations

There are great variations in life expectancy between different parts of the world, mostly caused by differences in public health Public health is "the science and art of preventing disease, prolonging life and promoting health through the organized efforts and informed choices of society, organizations, public and private, communities and individuals." It is concerned with threats to the overall health of a community based on population health analysis. The, medical care and diet. Much of the excess mortality (higher death rates) in poorer nations is due to war, starvation, and diseases (AIDS Acquired immune deficiency syndrome or acquired immunodeficiency syndrome is a disease of the human immune system caused by the human immunodeficiency virus (HIV). This condition progressively reduces the effectiveness of the immune system and leaves individuals susceptible to opportunistic infections and tumors. HIV is transmitted through direct, Malaria Malaria is a mosquito-borne infectious disease caused by a eukaryotic protist of the genus Plasmodium. It is widespread in tropical and subtropical regions, including parts of the Americas , Asia, and Africa. Each year, there are approximately 350–500 million cases of malaria, killing between one and three million people, the majority of whom, etc.). Over the past 200 years, countries with Black or African populations have generally not had the same improvements in mortality rates that have been enjoyed by populations of European origin. Even in countries with a majority of White people, such as USA, Britain, Ireland and France, Black people tend to have shorter life expectancies than their White counterparts (although often the statistics are not analysed by race). For example, in the U.S. White Americans are expected to live until age 78, but African Americans only until age 71.^[6]. Climate may also have an effect, and the way data is collected may also influence the figures. According to the CIA World Factbook The World Factbook is a reference resource produced by the Central Intelligence Agency of the United States with almanac-style information about the countries of the world. The official paper copy version is available from the National Technical Information Service and the Government Printing Office. Other companies—such as Skyhorse Publishing—, Macau Macau , also known as Macao (pronounced /məˈkaʊ/) is one of the two special administrative regions of the People's Republic of China, the other being Hong Kong. Macau lies on the western side of the Pearl River Delta, bordering Guangdong province to the north and facing the South China Sea in the east and south Special Administrative Region of the People's Republic of China b. ^ Simple characterizations of the political structure since the 1980s are no longer possible has the world's longest life expectancy of 84.4 years.

There are also significant differences in life expectancy between men and women in most countries, with women typically outliving men by around five years. Economic circumstances also affect life expectancy. For example, in the United Kingdom, life expectancy in the wealthiest areas is several years longer than in the poorest areas. This may reflect factors such as diet and lifestyle as well as access to medical care. It may also reflect a selective effect: people with chronic life-threatening illnesses are less likely to become wealthy or to reside in affluent areas.^[24] In Glasgow Glasgow (pronounced /ˈɡlæzɡoʊ/ ; Scots: Glesga Scottish Gaelic: Glaschu) is the largest city in Scotland and third most populous in the United Kingdom. The city is situated on the River Clyde in the country's west central lowlands. A person from Glasgow is known as a Glaswegian, which is also the name of the local dialect the disparity is among the highest in the world with life expectancy for males in the heavily deprived Calton Calton is a district in the Scottish city of Glasgow. The name Calton is derived from the Gaelic "coillduin", which means "wood on the hill". It is situated north of the River Clyde, and just to the east of the city centre. Calton's most famous landmark is the Barras street market and the world famous Barrowland Ballroom, one standing at 54 – 28 years less than in the affluent area of Lenzie Lenzie is a village situated by the Glasgow - Edinburgh railway in the East Dunbartonshire council area of Scotland, approximately six miles north-east of Glasgow city centre and one mile south of Kirkintilloch. It has a population of approximately 10,000 - due to increase by several thousand when a new residential development within the grounds, which is only eight kilometres away.^[25][26]

Life expectancy is also likely to be affected by exposure to high levels of highway air pollution Roadway air dispersion modeling is the study of air pollutant transport from a roadway or other linear emitter. Computer models are required to conduct this analysis, because of the complex variables involved, including vehicle emissions, vehicle speed, meteorology, and terrain geometry. Line source dispersion has been studied since at least the 19 or industrial air pollution Air pollution is the introduction of chemicals, particulate matter, or biological materials that cause harm or discomfort to humans or other living organisms, or damages the natural environment into the atmosphere.^{[citation needed]} This is one way that occupation can have a major effect on life expectancy. Well-educated professionals working in offices have a high life expectancy, while coal miners (and in prior generations, asbestos cutters) do not. Other factors affecting an individual's life expectancy are genetic disorders, obesity, access to health care, diet, exercise, tobacco smoking Tobacco smoking is the practice where tobacco is burned and the vapors either tasted or inhaled. The practice began as early as 5000–3000 BC. Many civilizations burnt incense during religious rituals, which was later adopted for pleasure or as a social tool. Tobacco was introduced to the Old World in the late 1500s where it followed common trade, drug use and excessive alcohol use.

Gender differences

Women tend to have a lower mortality rate at every age. In the womb, male fetuses have a higher mortality rate (babies are conceived in a ratio of about 124 males to 100 females, but the ratio of those surviving to birth is only 105 males to 100 females). Among the smallest premature babies (those under 2 pounds or 900 g) females again have a higher survival rate. At the other extreme, about 90% of individuals aged 110 are female.

In the past, mortality rates for females in child-bearing age groups were higher than for males at the same age. This is no longer the case, and female human life expectancy is considerably higher than those of men. The reasons for this are not entirely certain. Traditional arguments tend to favor socio-environmental factors: historically, men have generally consumed more tobacco Tobacco is an agricultural product processed from the leaves of plants in the genus Nicotiana. It can be consumed, used as an organic pesticide and, in the form of nicotine tartrate, it is used in some medicines. It is most commonly used as a recreational drug, and is a valuable cash crop for countries such as Cuba, China and United States, alcohol In chemistry, an alcohol is any organic compound in which a hydroxyl functional group (-O and drugs A drug, broadly speaking, is any substance that, when absorbed into the body of a living organism, alters normal bodily function. There is no single, precise definition, as there are different meanings in drug control law, government regulations, medicine, and colloquial usage than females in most societies, and are more likely to die from many associated diseases such as lung cancer Lung cancer is a disease of uncontrolled cell growth in tissues of the lung. This growth may lead to metastasis, which is the invasion of adjacent tissue and infiltration beyond the lungs. The vast majority of primary lung cancers are carcinomas of the lung, derived from epithelial cells. Lung cancer, the most common cause of cancer-related death, tuberculosis Tuberculosis or TB is a common and often deadly infectious disease caused by various strains of mycobacteria, usually Mycobacterium tuberculosis in humans. Tuberculosis usually attacks the lungs but can also affect other parts of the body. It is spread through the air, when people who have the disease cough, sneeze, or spit. Most infections in and cirrhosis of the liver Cirrhosis is a consequence of chronic liver disease characterized by replacement of liver tissue by fibrosis, scar tissue and regenerative nodules (lumps that occur as a result of a process in which damaged tissue is regenerated), leading to loss of liver function. Cirrhosis is most commonly caused by alcoholism, hepatitis B and C, and fatty liver.^[27] Men are also more likely to die from injuries, whether unintentional (such as car accidents A traffic collision is when a road vehicle collides with another vehicle, pedestrian, animal, road debris, or other geographical or architectural obstacle. Traffic collisions can result in injury, property damage, and death) or intentional (suicide Suicide is the term used for the deliberate self-destruction by a living being, resulting in their own death. Such actions are typically characterised as being made out of despair, or attributed to some underlying mental disorder which includes depression, bipolar disorder, schizophrenia, alcoholism and drug abuse. Financial difficulties,, violence, war).^[27] Men are also more likely to die from most of the leading causes of death (some already stated above) than women. Some of these in the United States include: cancer of the respiratory system, motor vehicle accidents, suicide, cirrhosis of the liver, emphysema, and coronary heart disease ^[6]. These far outweigh the female mortality rate from breast cancer and cervical cancer etc.

Some argue that shorter male life expectancy is merely another manifestation of the general rule, seen in all mammal species, that larger individuals tend on average to have shorter lives.^[28][29]. This biological difference occurs because women have more resistance to infections and degenerative diseases ^[6].

Influence of disabilities

The main disabilities influencing life expectancy are physical disabilities, including congenital conditions and the results of accidents.

In the Western world, people with a serious mental illness die on average 25 years earlier than the rest of the population^{[citation needed]}, even though there is no objective test for mental illness^{[citation needed]}. Mental illnesses include schizophrenia, bipolar disorder and major depression. Three out of five mentally ill die from mostly preventable physical diseases, such as Heart/Cardiovascular disease, Diabetes, Dyslipidaemia, Respiratory ailments, Pneumonia, Influenza.^{[citation needed]}

Stress also decreases life expectancy. The side effects of stress are: pain of any kind, heart disease, digestive problems, sleep problems, depression, obesity, autoimmune diseases, skin conditions, etc., all of which contribute to mental disorders, faster ageing, and other physical diseases.^{[citation needed]}

• Serious Mental Illness Suffer From Lack of Integrated Care, (Psychiatry News January 5, 2007 Volume 42, Number 1, page 5)
• Mentally ill die 25 years earlier, on average (USA Today)
• Premature Cardiovascular Disease (The Heart.org)
• Why Do the Mentally Ill Die Younger? (Time.com)

Centenarians

The number of centenarians is increasing at 7% per year, which means doubling the centanarian population every decade, pushing it into the millions in the next few years.^[30] Japan has the highest ratio of centenarians. In Okinawa, there are 34.7 centenarians for every 100,000 inhabitants ^[6].

In the United States, the number of centenarians grew from 15,000 in 1980 to 77,000 in 2000.^{[citation needed]}

Evolution and aging rate

Various species of plants and animals, including humans, have different lifespans. There is a well-developed evolutionary theory of aging, and general consensus in the academic community of evolutionary theorists; however the theory doesn't work well in practice, and there are many unexplained exceptions. Evolutionary theory states that organisms that, by virtue of their defenses or lifestyle, live for long periods whilst avoiding accidents, disease, predation, etc., are likely to have genes that code for slow aging - which often translates to good cellular repair. This is theorized to be true because if predation or accidental deaths prevent most individuals from living to an old age, then there will be less natural selection to increase intrinsic life span^[31]. The finding was supported in a classic study of opossums by Austad ^[32], however the opposite relationship was found in an equally-prominent study of guppies by Reznick ^[33][34]

One prominent and very popular theory attributes aging to a tight budget for food energy^[35]. The theory has difficulty with the caloric restriction effect, in which animals live longer the less food they eat.

In theory, reproduction is costly and takes energy away from the repair processes that extend life spans. However, in actuality females of many species invest much more energy in reproduction than do their male counterparts, and live longer nevertheless. In a broad survey of zoo animals, no relationship was found between the fertility of the animal and its life span.^[36]

One area in which theory seems to be well validated: Better-defended animals such as small birds and bats, that can fly away from danger, and naked mole rats that live underground, survive for decades, whereas mice, which cannot, die of old age in a year or two. Tortoises and turtles are very well defended and can live for over 100 years.

Calculating life expectancies

The starting point for calculating life expectancies is the age-specific death rates of the population members. A very simple model of age-specific mortality uses the Gompertz function, although these days more sophisticated methods are used.^[37]

In cases where the amount of data is relatively small, the most common methods are to fit the data to a mathematical formula, such as an extension of the Gompertz function, or to look at an established mortality table previously derived for a larger population and make a simple adjustment to it (eg multiply by a constant factor) to fit the data.

With a large amount of data, one looks at the mortality rates actually experienced at each age, and applies smoothing (eg by cubic splines) to iron out any apparently random statistical fluctuations from one year of age to the next.

While the data required is easily identified in the case of humans, the computation of life expectancy of industrial products and wild animals involves more indirect techniques. The life expectancy and demography of wild animals are often estimated by capturing, marking and recapturing them.^[38] The life of a product, more often termed shelf life is also computed using similar methods. In the case of long-lived components such as those used in critical applications, such as in aircraft methods such as accelerated aging are used to model the life expectancy of a component.^[3]

The age-specific death rates are calculated separately for separate groups of data which are believed to have different mortality rates (eg males and females, and perhaps smokers and non-smokers if data is available separately for those groups) and are then used to calculate a life table, from which one can calculate the probability of surviving to each age. In actuarial notation the probability of surviving from age x to age x+n is denoted and the probability of dying during age x (i.e. between ages x and x+1) is denoted . For example, if 10% of a group of people alive at their 90th birthday die before their 91st birthday, then the age-specific death probability at age 90 would be 10%.

The life expectancy at age x, denoted , is then calculated by adding up the probabilities to survive to every age. This is the expected number of complete years lived (one may think of it as the number of birthdays they celebrate).

Because age is rounded down to the last birthday, on average people live half a year beyond their final birthday, so half a year is added to the life expectancy to calculate the full life expectancy. (This is with a circle over the e.)

Life expectancy is by definition an arithmetic mean. It can also be calculated by integrating the survival curve from ages 0 to positive infinity (the maximum lifespan, sometimes called 'omega'). For an extinct cohort (all people born in year 1850, for example), of course, it can simply be calculated by averaging the ages at death. For cohorts with some survivors it is estimated by using mortality experience in recent years.

It is important to note that this statistic is usually based on past mortality experience, and assumes that the same age-specific mortality rates will continue into the future. Thus such life expectancy figures are not generally appropriate for calculating how long any given individual of a particular age is expected to live. But they are a useful statistic to summarize the current health status of a population.

However for some purposes, such as pensions calculations, it is usual to adjust the life table used, thus assuming that age-specific death rates will continue to decrease over the years, as they have done in the past. This is often done by simply extrapolating past trends; however some models do exist to account for the evolution of mortality (e.g., the Lee-Carter model^[39]).

As discussed above, on an individual basis, there are a number of factors that have been shown to correlate with a longer life. Factors that are associated with variations in life expectancy include family history, marital status, economic status, physique, exercise, diet, drug use including smoking and alcohol consumption, disposition, education, environment, sleep, climate, and health care.^[6]

Life Expectancy Index

The Life Expectancy Index is a statistical measure used to determine the average lifespan of the population of a certain nation or area. Life expectancy is one of the factors in measuring the Human Development Index (HDI) of each nation, along with adult literacy, education, and standard of living.^[40]

Life expectancy is also a factor in finding the physical quality of life of an area.

See also

• Biodemography
• Calorie restriction
• Demography
• DNA damage theory of aging
• Economics
• Indefinite lifespan
• Life table
• List of countries by life expectancy
• Maximum life span
• Medieval demography
• Mitohormesis
• Mortality rate
• List of long-living organisms
• Senescence
• Healthcare inequality

Increasing life expectancy

• Strategies for Engineered Negligible Senescence (SENS)
• John Sperling
• Life extension
• Longevity
• Rejuvenation
• Public health
• Infant mortality

References

1. ^ Sullivan, Arthur; Steven M. Sheffrin (2003). Economics: Principles in action. Upper Saddle River, New Jersey 07458: Pearson Prentice Hall. pp. 473. ISBN 0-13-063085-3. http://www.pearsonschool.com/index.cfm?locator=PSZ3R9&PMDbSiteId=2781&PMDbSolutionId=6724&PMDbCategoryId=&PMDbProgramId=12881&level=4.
2. ^ John S. Millar and Richard M. Zammuto (1983). "Life Histories of Mammals: An Analysis of Life Tables". Ecology 64 (4): 631–635. doi:10.2307/1937181.
3. ^ ^{a b} Eliahu Zahavi,Vladimir Torbilo & Solomon Press (1996) Fatigue Design: Life Expectancy of Machine Parts. CRC Press. ISBN 0849389704
4. ^ news.bbc.co.uk, BBC Country Profile: Swaziland (referencing UN data)
5. ^ Ansley J. Coale; Judith Banister (December 1996). "Five decades of missing females in China". Proceedings of the American Philosophical Society 140 (4): 421–450. http://links.jstor.org/sici?sici=0003-049X%28199612%29140%3A4%3C421%3AFDOMFI%3E2.0.CO%3B2-O. Retrieved 2007-05-26.
6. ^ ^{a b c d e f} Santrock, John (2007). Life Expectancy. A Topical Approach to: Life-Span Development(pp. 128-132). New York, New York: The McGraw-Hill Companies, Inc.
7. ^ Hillard Kaplan, Kim Hill, Jane Lancaster, and A. Magdalena Hurtado "A Theory of Human Life History Evolution: Diet, Intelligence and Longevity" (Evolutionary Anthropology, 2000, p. 156-185) - http://www.unm.edu/~hkaplan/KaplanHillLancasterHurtado_2000_LHEvolution.pdf
8. ^ Caspari & Lee 'Older age becomes common late in human evolution' (Proceedings of the National Academy of Sciences, USA, 2004, p. 10895-10900
9. ^ ^{a b} Galor.O "Natural selection and the evolution of life expectancy,2005
10. ^ ^{a b} Mortality (Britannica.com)
11. ^ Pre-European Exploration, Prehistory through 1540
12. ^ Conrad, Lawrence I. (2006). The Western Medical Tradition. Cambridge University Press. p. 137. ISBN 0521475643.
13. ^ Time traveller's guide to Medieval Britain
14. ^ A millennium of health improvement
15. ^ World Health Organization
16. ^ Our Special Place in History
17. ^ CIA - The World Factbook -- Rank Order - Life expectancy at birth
18. ^ "Medicine & Health", Stratfordhall.org.
19. ^ "Death in Early America". Digital History.
20. ^ "Modernization - Population Change". Encyclopædia Britannica.
21. ^ Mabel C. Buer, Health, Wealth and Population in the Early Days of the Industrial Revolution, London: George Routledge & Sons, 1926, page 30 ISBN 0-415-38218-1
22. ^ BBC - History - The Foundling Hospital. Published: 2001-05-01.
23. ^ CDC (1999). "Ten great public health achievements—United States, 1900–1999". MMWR Morb Mortal Wkly Rep 48 (12): 241–3. PMID 10220250. http://cdc.gov/mmwr/preview/mmwrhtml/00056796.htm. Reprinted in: "From the Centers for Disease Control and Prevention. Ten great public health achievements--United States, 1900-1999.". JAMA 281 (16): 1481. 1999. doi:10.1001/jama.281.16.1481. PMID 10227303.
24. ^ Department of Health -Tackling health inequalities: Status report on the Programme for Action
25. ^ "Social factors key to ill health". BBC News. 2008-08-28. http://news.bbc.co.uk/1/hi/health/7584056.stm#Life%20expectancy. Retrieved 2008-08-28.
26. ^ "GP explains life expectancy gap". BBC News. 2008-08-28. http://news.bbc.co.uk/1/hi/scotland/glasgow_and_west/7584450.stm. Retrieved 2008-08-28.
27. ^ ^{a b} World Health Organization (2004). "Annex Table 2: Deaths by cause, sex and mortality stratum in WHO regions, estimates for 2002" (pdf). The world health report 2004 - changing history. http://www.who.int/entity/whr/2004/annex/topic/en/annex_2_en.pdf. Retrieved 2008-11-01.
28. ^ http://jerrymondo.tripod.com/lgev/id1.html
29. ^ Samaras, Thomas T. und Heigh, Gregory H.: How human size affects longevity and mortality from degenerative diseases. Townsend Letter for Doctors & Patients 159: 78-85, 133-139
30. ^ http://www.usatoday.com/news/health/2005-10-23-aging-centenarians_x.htm
31. ^ Williams G (1957). "Pleiotropy, natural selection, and the evolution of senescence". Evolution 11: 398–411. doi:10.2307/2406060.
32. ^ Austad SN (1993). "Retarded senescence in an insular population of Virginia opossums". J. Zool. London 229: 695–708. doi:10.1111/j.1469-7998.1993.tb02665.x.
33. ^ Reznick DN, Bryant MJ, Roff D, Ghalambor CK, Ghalambor DE (2004). "Effect of extrinsic mortality on the evolution of senescence in guppies". Nature 431 (7012): 1095–1099. doi:10.1038/nature02936. PMID 15510147.
34. ^ Mitteldorf J, Pepper J (2007). "How can evolutionary theory accommodate recent empirical results on organismal senescence?". Theory in Biosciences 126 (1): 3–8. doi:10.1007/s12064-007-0001-0. PMID 18087751.
35. ^ Kirkwood TE (1977). "Evolution of aging". Nature 270 (5635): 301–304. doi:10.1038/270301a0. PMID 593350.
36. ^ Ricklefs RE, Cadena CD (2007). "Lifespan is unrelated to investment in reproduction in populations of mammals and birds in captivity". Ecol. Lett. 10 (10): 867–872. doi:10.1111/j.1461-0248.2007.01085.x. PMID 17845285.
37. ^ Anderson, Robert N. (1999) Method for constructing complete annual U.S. life tables. Vital and health statistics. Series 2, Data evaluation and methods research ; no. 129 (DHHS publication ; no. (PHS) 99-1329) PDF
38. ^ Linda J Young; Jerry H Young (1998) Statistical ecology : a population perspective. Kluwer Academic Publishers. p. 310
39. ^ Ronald D. Lee and Lawrence Carter. 1992. "Modeling and Forecasting the Time Series of U.S. Mortality," Journal of the American Statistical Association 87 (September): 659-671.
40. ^ http://hdrstats.undp.org/indicators/6.html

Further reading

• Leonid A. Gavrilov & Natalia S. Gavrilova (1991), The Biology of Life Span: A Quantitative Approach. New York: Harwood Academic Publisher, ISBN 3-7186-4983-7

External links

• Calculate your life expectancy online (based on the Austrian generation and annuity valuation life tables)
• Rank Order - Life expectancy at birth from the CIA's World Factbook.
• CDC year-by-year life expectancy figures for USA from the USA Centers for Disease Controls and Prevention, National Center for Health Statistics.
• Life expectancy in Roman times from the University of Texas.
• Database of life expectancy from multiple countries from The human Mortality Database.
• Animal lifespans: Animal Lifespans from Tesarta Online (Internet Archive); The Life Span of Animals from Dr Bob's All Creatures Site.
• Life expectancy among the countries in the European Union (2007)
• Scientists Have Found the Gene That Decides How Long We Live
• Hans Rosling presents animated data showing global life expectancy from 1820-2020 (video) from TED Conference
• Information on life expectancy

Categories: Actuarial science | Aging | Demography | Population | Gerontology | Demographic economics

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• Life Extension: Encyclopedia
• Maximum Lifespan: Encyclopedia
• Maximum Life Span: Encyclopedia
• Indefinite Lifespan: Encyclopedia

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