How has a longer lifespan affected the perspective of mankind?

Population development

Herwig Birg

To person

Prof. Dr. rer. pole. habil. From 1981 to 2004, Herwig Birg was head of the chair for population science and managing director of the Institute for Population Research and Social Policy (IBS) at Bielefeld University. His main research areas are population theory, fertility theory, migration theory, mortality analysis and life expectancy, population forecasting and simulation models, and population projections. Contact: »[email protected]« Homepage: »«

Falling birth rates are affecting the functionality of the previous social security system in Germany. This has consequences for pension, health and long-term care insurance as well as for the economy and the settlement structure. Immigration is one factor that can, in some ways, influence these consequences.

A carer massages the hand of an old woman in a senior citizen center in Stuttgart. (& copy AP)


Every curriculum vitae can be broken down into three basic phases: In the child and youth phase, young people who are still developing are dependent on the support of the economically active members of their parents' generation. When he himself reaches the phase of economic independence and becomes a member of the next, new generation of parents, his status changes from beneficiary to provider: on the one hand, he supports the now older members of his parents' generation, on the other hand, the young offspring of his own generation. In the third phase, as an older person, he returns to the status of the recipient of support services that must now be earned by the descendants of his own generation who have moved on to the middle phase.

In the course of their lives, every person is first of all a recipient, then a supporter and finally a recipient of the services of others and to other generations. Increasing life expectancy means that more and more people not only live with members of the generations of their parents and grandparents, but also with their great-grandparents.

The interweaving of the generations through services and considerations in return is referred to in Germany as a generation contract, although this contract is not binding in writing or in any other form. The essential prerequisite for its effectiveness is the voluntary willingness to recognize the mutual obligations of the generations involved. It is important that three generations are always directly involved in the generation contract, not just two. Because every person receives twice in his life the support of other generations, who face two considerations for the generations of his parents and his descendants.

This fact is correctly designated by the term "three-generation contract", while the expression "two-generation contract" encourages the mistake that the middle generation, through their payments into the statutory pension insurance, for example, is already providing benefits for their own Would have provided care in old age. With these payments, the middle generation only returns the benefits they received in their childhood and adolescence to their parents' generation. Their own provision in old age is only generated by the generation of their descendants. The functionality of the intergenerational contract or the security of care in old age therefore depends crucially on the size of the successive generations who receive and provide care. This proportion is largely determined by the birth rate.

If the birth rate is low, the burden on the middle generation from services to the younger is low, but the burden from the service to the elderly is all the higher because these services have to be provided by a middle generation, which is relatively due to the low birth rate has few members. The burden on the middle generation per capita of its members can be determined by the youth quotient (number of under 15-year-olds per 100 people from 15 to under 65 years of age) and the old-age quotient (number of over 65-year-olds per 100 people from 15 to under 65 years of age ) specify. The sum of the youth and old age quotient is referred to as the support quotient.

For example, Germany had an old-age quotient of 23 in 2000 and 31 in 2010, i.e. a group of 100 people aged 15 to under 65 had 23 people aged 65 and over in 2000 in 2010 it was already 31. With a higher birth rate of two children per woman, for example, the old-age ratio would also increase by 2050, to 36.8, but with three children per woman it would only increase to 21.3.

If the number of children remained constant at the current level of 1.4 per woman and mortality or life expectancy constant, the old-age ratio (excluding immigration of younger people) would rise to 57.3, i.e. more than double compared to 2000 - with all the consequences for the social security systems.