Maximum lifespan is the age at death for the longest-lived individual of a species. Because life expectancy is an average, a particular person may die many years before or many years after the "expected" survival. Life expectancy is also used in plant or animal ecology, and in life tables (also known as actuarial tables).
Life expectancy. The term life expectancy may also be used in the context of manufactured objects, but the related term shelf life is used for consumer products, and the terms "mean time to breakdown" (MTTB) and " mean time between failures " (MTBF) are used in engineering.
Life expectancy. Life expectancy is a statistical measure of the average time an organism is expected to live, based on the year of its birth, its current age and other demographic factors including gender.
^ Hawks, John (2009), Human lifespans have not been constant for the last 2000 years. Leonid A. Gavrilov & Natalia S. Gavrilova (1991), The Biology of Life Span: A Quantitative Approach.
Further, there are many examples of people living significantly longer than the average life expectancy of their time period, such as Socrates (71), Saint Anthony the Great (105), Michelangelo (88), and John Adams, 2nd president of the United States (90).
Life expectancy is a statistical measure of the average time an organism is expected to live, based on the year of its birth, its current age, and other demographic factors including biological sex. The most commonly used measure is life expectancy at birth ( LEB ), which can be defined in two ways.
Life expectancy forecasting is usually based on two different approaches: 1 Forecasting the life expectancy directly, generally using ARIMA or other time-series extrapolation procedures: that has the advantage of simplicity, but it cannot account for changes in mortality at specific ages, and the forecast number cannot be used to derive other life table results. Analyses and forecasts using this approach can be done with any common statistical/mathematical software package, like EViews, R, SAS, Stata, Matlab, or SPSS. 2 Forecasting age-specific death rates and computing the life expectancy from the results with life table methods: that is usually more complex than simply forecasting life expectancy because the analyst must deal with correlated age-specific mortality rates, but it seems to be more robust than simple one-dimensional time series approaches. It also yields a set of age specific-rates that may be used to derive other measures, such as survival curves or life expectancies at different ages. The most important approach within this group is the Lee-Carter model, which uses the singular value decomposition on a set of transformed age-specific mortality rates to reduce their dimensionality to a single time series, forecasts that time series and then recovers a full set of age-specific mortality rates from that forecasted value. The software includes Professor Rob J. Hyndman 's R package called `demography` and UC Berkeley's LCFIT system.
According to projections made by the United Nations (UN) in 2002, the life expectancy at birth for 2010–2015 (if HIV/AIDS did not exist) would have been: 70.7 years instead of 31.6 years, Botswana. 69.9 years instead of 41.5 years, South Africa. 70.5 years instead of 31.8 years, Zimbabwe.
If we do not take into account child mortality in total mortality, then the average life expectancy in the 12–19 centuries was approximately 55 years. If a medieval person was able to survive childhood, then he had about a 50% chance of living up to 50–55 years.
Another measure, such as life expectancy at age 5 (e 5 ), can be used to exclude the effect of infant mortality to provide a simple measure of overall mortality rates other than in early childhood; in the hypothetical population above, life expectancy at 5 would be another 65.
Maximum lifespan is the age at death for the longest-lived individual of a species. Moreover, because life expectancy is an average, a particular person may die many years before or many years after the "expected" survival. The term " maximum lifespan " has a quite different meaning and is more related to longevity.