How is tfr measured

The TFR is the most widely used fertility measure in program impact evaluations for two main reasons: 1 it is unaffected by differences or changes in age-sex composition, and 2 it provides an easily understandable measure of hypothetical completed fertility. TFR includes only live births. The TFR is only a hypothetical measure of completed fertility, and thus women of reproductive age at any given point in time could have completed family sizes considerably different from that implied by a current TFR, should age-specific fertility rates rise or fall in the future.

As was also the case for the ASFR, the TFR may be computed for women who were continuously married or in union during the reference period of the measure in order to decrease the potentially confounding effects of differences in exposure to the risk of pregnancy to the extent that differences are associated with marital status.

Total fertility rate. Data Source s : Vital statistics numerator only , population censuses or population-based surveys. We observed this phenomenon in , where the number of Singapore Citizen births increased for example, there were 32, births in compared to 32, births in , , yet TFR declined to 1.

While there were more babies, the number of women entering the peak child-bearing age groups years had also risen. These women were born in the decade starting from , and many of them are children of the Baby Boomer generation.

Compared to earlier cohorts, more of them were not yet married or had not started having children yet. From the formula above, we can see that the number of marriages does not directly affect TFR, since it is not in the numerator or the denominator.

Similarly, TFR is not directly affected by the age at first marriage or age at first birth. What is more important is the number of births women have on average, regardless of the age at which they get married or have children.

However, there may be indirect effects, as data in Singapore shows that women who get married and start having children earlier tend to have more children over their lifetime. A Singapore government agency website. How to identify. Official website links end with. Who We Are. Our Population Overview Population Trends.