Table of Contents
- The Reality of a Serious Population Crisis
- What is Population Halving?
- TFR 0.8 Scenario: A Shocking 25-Year Population Halving
- 25 Years of Population Halving: What Does the Future Hold?
- Comparing Population Halving by Birth Rate Scenarios
- Population Crisis: Fundamental Change and Adaptation Are Urgent
The Reality of a Serious Population Crisis
Currently, South Korea is facing an unprecedented low birth rate problem historically.
The total fertility rate (TFR) has steadily decreased to 0.72 in 2023, the lowest among OECD member countries. In 2024, it showed a slight recovery to 0.75, but the phenomenon of 'ultra-low birth rates' that has persisted for more than 20 years indicates a serious situation.
This low birth rate issue is impacting society as a whole and urgent solutions are needed.
South Korea's serious low birth rate problem is causing various socioeconomic issues. As the population ages, the potential workforce is decreasing, resulting in a decline in potential growth rates and increasing burdens on social security systems.
This has raised concerns about a 'population halving,' where the population could decrease by half.
This post aims to analyze the potential for population halving resulting from changes in total fertility rates in depth.
What is Population Halving?
In demography, 'population halving' (T1/2) refers to the theoretical time required for a specific population to reduce to half its current size while maintaining a persistent negative intrinsic natural increase rate, ultimately reaching a stable age structure.
Population halving is an important indicator that represents the long-term rate of population decline when specific birth and death rates are sustained. This indicator is calculated using the intrinsic natural increase rate (r) through the formula T1/2 = -r ln(2), where ln(2) is approximately 0.69315.
If the low birth rate trend continues, this indicator helps intuitively understand the severity of the population decline. Therefore, various measures are needed to address the population decline issue.
TFR 0.8 Scenario: A Shocking 25-Year Population Halving
If South Korea's total fertility rate remains at 0.8, the population halving will occur very quickly. This is expected to have serious impacts on society and the economy. Population decline can trigger various problems.
The analysis results are shocking.
First, estimating the net reproduction rate (NRR) is necessary. NRR is an indicator that shows how many daughters are born on average during a woman's fertile period, reflecting female mortality as well. In Korea, NRR can be approximated by dividing TFR by about 2.05. For example, when TFR is 0.8, NRR corresponds to about 0.390, meaning that one generation reproduces only about 39% of the previous generation.
This data suggests various social issues related to population decline. Therefore, changes in NRR will play a crucial role in determining future population structures and policy directions.
Next, let’s determine the average generational interval (T). This indicates the average age of mothers at childbirth. As of 2023, the average age of mothers in Korea is about 33.6 years.
Using this information, we can calculate the intrinsic natural increase rate (r). According to stable population theory, r is calculated using the formula r = ln(NRR) / T.
In the TFR = 0.8 scenario, r is about -0.02801, indicating that the population is expected to naturally decline at a rate of about 2.80% per year. This figure serves as an important reference for future population changes.
By applying the value of r to the population halving formula (T1/2 = -ln(2)/r), the population halving in the TFR 0.8 scenario is estimated to be about 25 years. This theoretically suggests the possibility that the population could halve approximately every 25 years, which is shorter than the current average generational interval of 33.6 years.
This estimate is based on theoretical assumptions that do not consider fixed birth and death rates, a stable age structure, and international migration. Actual population changes can be affected by various future factors. Nonetheless, the long-term potential 'speed' of population decline implied by a TFR of 0.8 must be taken seriously.
Therefore, we need to be vigilant of these warnings and seek solutions to population issues.
25 Years of Population Halving: What Does the Future Hold?
Previously, we examined the potential impacts if South Korea's total fertility rate (TFR) falls sharply. An analysis of recent data based on demographic principles suggests that if the TFR remains at 0.8, it could theoretically take about 25 years for the population to halve. This means that under the assumption that other variables (e.g., changes in death rates, international migration, etc.) are excluded, the population could decrease by half every 25 years if current birth and death rates remain unchanged.
If this prediction materializes, we will specifically examine how the future population may change based on the estimated population of 50 million in 2025. The changes are expected to have significant impacts across society.
| Year | Estimated Population (millions) |
| 2025 | 50.0 |
| 2050 | 25.0 |
| 2075 | 12.5 |
| 2100 | 6.25 |
| 2125 | 3.12 |
| 2150 | 1.56 |
From the table, it can be observed that if the 25-year population halving is maintained theoretically, the population could shrink to about 25 million by 2050, 12.5 million by 2075, and only 6.25 million by 2100. By 2150, there is also a possibility of the population dropping below 1.56 million.
It should be emphasized that this prediction is a theoretical model based on fixed assumptions, maintaining TFR at 0.8 and the current death rates, without accounting for international migration. In reality, future populations will be impacted by various factors such as birth rates, changes in death rates, government policies, and international migration levels.
However, this prediction clearly demonstrates the potential long-term consequences if the ongoing trend of ultra-low birth rates does not change. It suggests that we seriously need to consider future population issues.
Comparing Population Halving by Birth Rate Scenarios
To better understand the severity of the TFR 0.8 scenario, a comparison with other TFR scenarios will be conducted. Here, the average generational interval is assumed to be 33.6 years.
For TFR 1.0, the net reproduction rate (NRR) is approximately 0.488, with an annual decline rate of about -2.14%. In this case, the population halving is expected to take about 32 years.
Next, if we look at the TFR 1.5 scenario, the NRR reaches about 0.732, with an annual decline rate of -0.93%. Here, the population halving is estimated to be about 75 years.
For TFR 2.0, the NRR is approximately 0.976, with an annual decline rate of almost negligible -0.07%. In this case, the population halving is expected to take about 940 years.
For reference, near the replacement level of TFR 2.1, NRR is 1.024, showing an annual increase rate of +0.07%. In this scenario, the population increases, and there is no halving. Such comparisons can further highlight the seriousness of the TFR 0.8 scenario.
The analysis results indicate that population halving highly responds to changes in total fertility rate (TFR). Especially, as TFR approaches the population replacement level of approximately 2.1, the halving period tends to extend.
If TFR is below 1.0, it indicates a demographically very serious situation. For instance, the halving periods for TFRs of 0.8 and 1.0 (25 years and 32 years respectively) are comparable to or shorter than a generational span, suggesting that the population decline may occur very rapidly.
Population Crisis: Fundamental Change and Adaptation Are Urgent
The estimates of population halving are based on merely hypothesized figures, but they clearly reveal the serious analysis of Korea's ultra-low birth rate problem and long-term population decline. The fact that a very short halving period of about 25 years appears when TFR is at 0.8 strongly suggests that the current population crisis is not just a transient change, but a serious situation threatening the existence of society.
This drastic decline in birth rates and the population can lead to various socioeconomic problems. The decrease in the working-age population leads to a decline in potential growth rates, while the contraction of the domestic market negatively affects the entire economy. Additionally, the sustainability of social security systems is increasingly threatened, generational conflicts intensify, and the shortage of military resources also emerges as a serious issue.
These problems are not merely statistical figures but aspects that directly impact our lives, making them clearly topics we need to reflect on seriously.
Population decline must now be accepted as an inevitable reality. Consequently, it is necessary to restructure the systems in various areas such as the economy, society, culture, welfare, education, and national defense to fit the population decline era. We need to find a combination of effective policies based on in-depth analysis of the fundamental causes of the low birth rate. Furthermore, efforts to enhance the responsiveness of society as a whole to changes in population structure are urgently needed. This process must proceed without delay.
#SouthKoreaBirthRate, #TotalFertilityRate, #LowBirthRate, #UltraLowBirthRate, #PopulationCrisis, #PopulationDecline, #PopulationCliff, #PopulationHalving, #TFR, #NRR, #NetReproductionRate, #AverageGenerationalInterval, #IntrinsicNaturalIncreaseRate, #Demography, #SocialIssues, #EconomicCrisis, #PotentialGrowthRate, #WorkingAgePopulation, #AgingSociety, #SuperAgedSociety, #SocialSecuritySystem, #NationalPension, #HealthInsurance, #GenerationalConflict, #PopulationPolicy, #LowBirthRateMeasures, #ImmigrationPolicy, #FutureOutlook, #ExtinctionOfKoreans, #ChangesInSocialSystems
