Completed cohort fertility

From Demography
Jump to: navigation, search

Definition

General definition

The completed cohort fertility (CCF), also called the cohort completed fertility or completed fertility rate (CFR) for a cohort of females (typically, a birth cohort) who have all completed their childbearing years is the arithmetic mean of the values of completed fertility for all females in that cohort.

For a given birth order

Suppose is a positive integer. The completed cohort fertility at birth order for a given birth cohort is the fraction of people in that birth cohort that have a birth at birth order .

Variants

Completed fertility rates can be computed only for cohorts that have completed their childbearing years. This creates a huge time lag: we can only calculate completed fertility rates for cohorts that were born 49 or more years ago.

Some sources, such as the Human Fertility Database, provide a piece of information called CCF40: this is the parity at age 40 for the cohort. This may also be broken down by birth order.

Data collection

Data collection challenges

There are two main disadvantages of CCF relative to other types of fertility data such as the total fertility rate:

  • CCF is available only after a time lag. We can calculate CCF only for birth cohorts that have completed their childbearing years, which means birth cohorts that were born at least 49 years ago. This is so even though most women have babies before the age of 40. Note that the related measure CCF40 overcomes this problem, but this data is also lagged and fails to adequately capture what is happening to fertility at present.
  • Computation of CCF data requires considerably more demographic information than computation of the total fertility rate.

Broadly, there are two ways that CCF data could be measured:

  1. Direct measurement: For all births, the birth cohort of the mother at the time of birth is recorded. Thus, it is possible to put together the data and calculate the total number of children had to women from a particular birth cohort.
  2. Estimation: Surveys are used based on appropriate sampling methodology and the results are interpreted.

Data sources

Data source Data available
United Nations data No direct data available
Gapminder (synthesis of data from multiple sources) No direct data available
Human Fertility Database CCF and CCF40 data available for some OECD countries. Last year for CCF data is the 1960 birth cohort and last year for CCF40 data is the 1969 birth cohort. For some years, the data is available by birth order as well. The country list is Austria, France, Norway, Switzerland, Bulgaria, Germany, Portugal, Taiwan, Canada, Hungary, Russia, U.K., Czech Republic, Japan, Slovakia, U.S.A., Estonia, Lithuania, Slovenia, Ukraine, Finland, Netherlands, Sweden

Values

Most recent values

Values here are based on the Human Fertility Database, a highly reliable source, but one that is limited to a few countries.

Country Fertility information CCF (1960 birth cohort) CCF (1959 birth cohort) CCF (1958 birth cohort) CCF (1957 birth cohort)
Japan Fertility in Japan 1.87 1.909 1.918 1.946
Germany Fertility in Germany 1.659 1.661 1.662 1.666
Russia Fertility in Russia 1.849 1.86 1.862 1.874
USA Fertility in USA 2.018 2.01 1.994 1.986

Below are the CCF40 values, that are available for birth cohorts till as late as 1969 or 1970.

Country Fertility information CCF (1970 birth cohort) CCF (1969 birth cohort) CCF (1968 birth cohort) CCF (1967 birth cohort)
Japan Fertility in Japan unavailable 1.444 1.497 1.506
Germany Fertility in Germany 1.453 1.445 1.446 1.458
Russia Fertility in Russia 1.572 1.587 1.6 1.611
USA Fertility in USA 2.068 2.055 2.061 2.062