For a definition shown, click on the alphabet and the word of your choice, or enter a keyword in the "search word" then enter. This glossary will be updated regularly with new definitions.
Replacement of generations
Replacement of generations designates the replacement number-for-number of the generations of ages to have children by generations being born. The replacement of the generation of mothers is measured by comparing the number of women in a generation with the number of their daughters. Replacement is guaranteed if there are as many daughters as there are mothers.
It is possible to measure the replacement at birth (are as many daughters being born as there are women in the generation of the mothers) or at various ages. Replacement of a generation at birth depends on its fertility and on its mortality. Replacement at a given age further depends on the mortality of the daughters compared with the mortality of the mothers. When mortality decreases, the replacement is greater if it is measured at a higher age. Thus, the 1950 generation did not guarantee its replacement at birth, but it did at age 15. Infant mortality dropped considerably between 1950 and 1978, the year when the daughters whose mothers were born in 1950 were born on average. And 100 young women of 15 born in 1950 had on average 100 daughters who were alive at the age of 15.