Economic Fertility Index (CFI)

The cyclical fertility index represents the number of children that 15-year-olds would give life before age 49 if they adopted fertility by age group observed during that period. The cyclical fertility index is calculated here over a 5-year period, starting from the fertility rates of women aged 15 to 49. It is the sum of fertility rates per five-year age group multiplied by 5. Fertility rates by age group reflect in the numerator the average annual number of live births for women in a given age group. The denominator is the average for the period analysed of the populations on 1 July of women in this same age group. The cyclical fertility index is an indicator of population renewal that is not influenced by the age structure of the population, unlike the crude birth rate. It is therefore an excellent comparative indicator of the fertility of a population. Population renewal is ensured if the number of girls in the child generation is equal to the number of women in the parent generation. In the absence of mortality, a woman must give birth to 2.05 children (2.05 and not 2 because she is born 105 boys per 100 girls) to replace a generation, either herself and the father.