The recent decades saw developing countries experiencing the so-called “demographic transition” — a transition from high birth and death rates to lower birth and death rates that are seen in more developed countries.
This can be seen through the total fertility rate (TFR), a demographic indicator that estimates the average number of live children that a woman would have over her childbearing years of age 15-49 based on current birth trends.
To illustrate, estimates by the United Nations put the TFR of the Philippines at 7.42 live births per woman in the 1950-1955 period, higher than the Southeast Asian average of 5.93 live births per woman.
While the Philippines managed to bring down TFR by 58.9% to 3.05 live births per woman in the 2010-2015 period, this is still above the regional average of 2.35 births per woman as other countries saw faster decelerations in their TFRs during those decades.
The Philippine TFR is also above the 2.1 births per woman replacement rate i.e. the rate at which women give birth to babies just enough to sustain population levels (assuming normal boy-girl sex ratio and low levels of mortality). — BusinessWorld Research / Christine Joyce S. Castañeda
Data Source: World Population Prospects: The 2017 Revision (United Nations, Department of Economic and Social Affairs, Population Division 2017)