2017 - A Long Lifespan, but Not for All
How social divisions affect life expectancy
Alongside the birth rate and the balance between immigration and emigration, the
mortality rate is a major factor in demographic developments. It is usually expressed
in terms of the number of deaths per 100,000 inhabitants, either overall or classified
according to age group and cause of death.
In order to assess the mortality of a population independently of its size and age
structure, mortality tables are used. These contain statistical models based on data
about the number and age of those who have died over a certain period as well as about
the average population. This allows the probability of mortality for persons of a certain
age to be calculated. A mortality table shows, for each gender, how many people who
were alive at the beginning of the period in question have died and how many are still
alive.
The probable average life expectancy for a particular birth cohort can be calculated
using the mortality tables for the previous period. In Germany, official statistics record
mortality for periods of three years. Thus current life expectancy figures are derived
from the trend discernible in the mortality tables for 2013 to 2015, which is used
to predict how long those born today will live on average – assuming that mortality
conditions remain constant.
The mortality tables for each period can also be used to determine how long a particular
age group, say the 60 or 65 year olds, can expect to live on average. This is called ageadjusted
life expectancy or life expectancy at that age. In statistical terms, today’s
pensioners may have a longer average overall life expectancy than today’s newborns,
since people who have lived beyond their 65th birthday have already left many
mortality risks behind them.9 Unless otherwise specified, life expectancy in this study
always refers to life expectancy at birth. Depending on the source and point in time
when the calculation is made, there may be some discrepancy in the given values, since
full data sets are not available for all countries.