Over the last decade, Japan’s population has aged more and more, to the point where more than a quarter of Japanese were 65 years and older in 2022. Population growth has stopped and even reversed, since it’s been in the red for several years now.

It’s getting old

With almost 30 percent of its population being elderly inhabitants, Japan is considered the “oldest” country in the world today. Japan boasts a high life expectancy, in fact, the Japanese tend to live longer than the average human worldwide. The increase of the aging population is accompanied by a decrease of the total population caused by a sinking birth rate. Japan’s fertility rate has been below the replacement rate for many decades now, mostly due to economic uncertainty and thus a decreasing number of marriages.

Are the Japanese invincible?

There is no real mystery surrounding the ripe old age of so many Japanese. Their high average age is very likely due to high healthcare standards, nutrition, and an overall high standard of living – all of which could be adopted by other industrial nations as well. But with high age comes less capacity, and Japan’s future enemy might not be an early death, but rather a struggling social network.

In 2023, around **** percent of the total population in Japan was aged 65 years and older. Due to a low birth rate and high longevity, people aged 65 years and over were estimated to make up approximately **** percent of the population in Japan by 2070. The share of children below 15 years old was expected to decrease to around *** percent by that year.

In 2020, around *** percent of the population in depopulated areas in Japan were aged 85 or older, as opposed to the national average of *** percent. The largest difference between the national average and depopulated areas could be observed among people aged 60 and older.

The statistic shows the total population in Japan from 2020 to 2024, with projections up until 2030. In 2024, the total population of Japan amounted to around 123.89 million inhabitants. See the figures for the population of South Korea for comparison. Total population in Japan From steadily low fertility rates to a growing elderly population, it is no secret that Japan’s population is shrinking. Population growth rates jump around a little, but are currently following a declining trend. The post-war baby boom generation is now in the 65-and-over age group, and the percentage of the population in that category is expected to keep growing, as is indicated by a high median age and high life expectancy. Japan already has the highest percentage of its population over 65 in the world, and the aging population puts some pressure on the Japanese government to provide welfare services for more people as rising numbers leave the workforce. However, the amount of jobs opened up for the younger generations by the older generations leaving the workforce means that unemployment is kept to a minimum. Despite a jump in unemployment after the global recession hit in 2008, rates were almost back to pre-recession rates by 2013. Another factor affecting Japan is the number of emigrants to other countries. The United States absorbs a number of emigrants worldwide, so despite a stagnating birth rate, the U.S. has seen a steady rise in population.

Japan is one of the highly urbanized and severely aging society. In an aging society, chronic disease and disability are prevalent, and the population is sensitive to environmental issues and climate change. To detect the impacts of population changes, formulate the population and public health policies, and assist environmental applications, the high-resolution and accurate gridded population dataset is strongly desired. To provide basic data for these studies, we create an open access annual dataset containing the total, male, and female population counts in each grid at a 500-m resolution from 2001 to 2020. The yearly population dataset is based on the 4th-level mesh data from the Statistics Bureau of Japan to make it easy to use. The dataset is provided here alongside the descriptions of the data and methods used in the fitting, cross-validation, and prediction processes.

The total population data are stored in 20 attributes, named the “X0000” style. The “0000” of “X0000” represents the four-digit year. For example, the attribute “X2001” reports the total 2001 population in the mesh. The dataset also preserves the direct output from the random forest and the logarithms of the total population. The attributes of the logarithms of the total population in each year are named in “X0000_log” style. The “0000” of “X0000_log” also stands for the four-digit year. The attributes of the female population, the logarithm of the female population, the male population, and the logarithm of the male population are written as “X0000_fema”, “X0000_fe_l”, “X0000_male”, and “X0000_ma_l”, respectively.

The accuracy of the models constructed to predict the total, male, and female populations are 92.09%, 91.92%, and 92.16%, respectively.

The world's most accurate population datasets. Seven maps/datasets for the distribution of various populations in Japan: (1) Overall population density (2) Women (3) Men (4) Children (ages 0-5) (5) Youth (ages 15-24) (6) Elderly (ages 60+) (7) Women of reproductive age (ages 15-49).

Text A, Representation theorem for a right eigenvector of an irreducible non-negative matrix. Text B, Theorem for infinite series expansion of characteristic equation. Text C, Original definition of type-reproduction number. Text D, Extension theorem of type-reproduction number. (ZIP)

According to a projection made in 2023, it was forecast that the number of people aged 65 years or older in Japan would increase from about **** million in 2024 to around ** million people by 2033. By contrast, the number of children, as well as the working-age population, was forecast to shrink in the same period.

This bar chart displays population (people) by countries yearly using the aggregation sum in Japan. The data is about countries per year.

In Japan, ** percent of the population was 65 years or older in 2024, underlining the aging population of the country. Among the G7, Germany and Italy had a higher share of people aged 65 years or more than of the inhabitants aged zero to 19 years. The United States had the highest share of children and youth between zero and 19 years at nearly ** percent.

The Japanese Archipelago consists of a series of isolated yet interconnected islands off the Eurasian continent. The linear topography of the archipelago presents a unique biogeographic context for the dispersal of organisms from the continent. In this study, mitochondrial DNA (mtDNA) and single-nucleotide polymorphism (SNP) variation were employed to elucidate the dispersal history of the Japanese clouded butterfly (Parnassius glacialis) across the Japanese Archipelago, including the northern island (Hokkaido), the main island (Honshu), and Shikoku Island. Network analysis of 1192 bp of mtDNA (cytochrome oxidase I and II) regions revealed 49 haplotypes and three distinct haplotype groups, which correspond geographically to Eastern Japan, Western Japan, and Chugoku–Shikoku. The Chugoku–Shikoku group is the most ancient lineage. Divergence time estimates using whole-genome sequencing of mtDNA suggest that the Japanese lineage diverged from the continental P. glacialis approximately 3.08 ..., SNPs were detected from the extracted DNA using the genotyping by random amplicon sequencing, direct (GRAS-Di) method designed by Enoki and Takeuchi (2018) and described by Hosoya et al. (2019); this method offers simple library construction and the capacity to detect many SNPs. Briefly, libraries were constructed through two sequential PCR steps, similar to multiplexed inter-simple sequence repeat genotyping by sequencing (Suyama and Matsuki 2015). The first PCR primers consisted of 10 bases of Illumina Nextera adaptor 3-end sequences plus 3-base random oligomers (13 bases). The final PCR product was purified using columns or magnetic beads without size selection and then employed for sequencing on an Illumina platform (Illumina, San Diego, CA, USA). Cyclized DNA was prepared using the produced library and the MGIEasy universal library conversion kit (App-A, MGI Tech) according to the manufacturer’s instructions. DNBs were prepared using the DNBSEQ DNB Rapid Make reagent kit (MGI Tech)..., , # Dual expansion routes likely underlie the present-day population structure in a Parnassius butterfly across the Japanese Archipelago

https://doi.org/10.5061/dryad.69p8cz9d3

Description of the data and file structure

Each sample’s raw fastq sequence data for SNP and haplotype of mtDNA

Files and variables

File: Supporting_Material_PG.xls

Description: Each sample’s raw fastq sequence data and haplotype

Variables

• Sheet 1: an overview of each sheet.
• Sheet 2: raw sequence data for each  SNP detected with the Grass-Di method.
• Sheet 3: haplotype number for each collected individual (collected year, individual code, collection site, Prefecture, Prefecture number, haplotype number)

In 2023, people aged 65 years and older in Japan accounted for approximately **** percent of the total Japanese population. Due to a low birth rate and high longevity, people aged 65 years and older were estimated to make up almost ** percent of the population in Japan by 2070.

【リソース】Volume 1_5-1_Trends in deaths, death rates (per 1,000 population) by sex and sex ratio:Japan / Volume 1_5-2_Trends in crude death rates and age-adjusted death rates (per 1,000 population) by sex:Japan / Volume 1_5-3_International comparison of crude death rates and age-standardized death rates (per 100,000 population) / Volume 1_5-4_Trends in deaths and death rates (per 1,000 population) by month:Japan / Volume 1_5-5_Trends in deaths by place of occurrence:Japan / Volume 1_5-6_Trends in percent distribution of deaths by place of occurrence:Japan / Volume 1_5-7_Deaths by place of occurrence:Japan, each prefecture and 21 major cities, 2017 / Volume 1_5-8_Percent distribution of deaths by place of occurrence:Japan, each prefecture and 21 major cities, 2017 / Volume 1_5-9_Trends in deaths by each prefecture:Japan / Volume 1_5-10_Trends in death rates (per 1,000 population) by each prefecture:Japan / Volume 1_5-11_Trends in leading causes of death:Japan / Volume 1_5-12_Trends in deaths and death rates (per 100,000 population) by sex and causes of death:Japan / Volume 1_5-13_Trends in deaths and death rates (per 100,000 population) by sex and causes (the condensed list of causes of death for Japan):Japan / Volume 1_5-14_Trends in age-adjusted death rates (per 100,000 population) by sex and causes of death:Japan / Volume 1_5-15_Trends in deaths and death rates (per 100,000 population) by sex, age and causes of death:Japan / Volume 1_5-16_Death rates (per 100,000 population) by sex, age and causes (the condensed list of causes of death for Japan):Japan, 2017 / Volume 1_5-17_Leading causes of death by sex and age:Japan, 2017 / Volume 1_5-18_Death rates (per 100,000 population) by causes (the condensed list of causes of death for Japan) by month:Japan, 2017 / Volume 1_5-19_Death rates (per 100,000 population) by causes (the condensed list of causes of death for Japan):Japan, each prefecture and 21 major cities, 2017 / Volume 1_5-20_Leading causes of death:Japan, each prefecture and 21 major cities, 2017 / Volume 1_5-21_Trends in deaths and percent distribution from leading causes of death by sex and place of occurrence:Japan / Volume 1_5-22_Deaths and percent distribution from leading causes of death by sex, age and place of occurrence:Japan, 2017 / Volume 1_5-23_Deaths and percent distribution by causes (the selected list of causes of death for Japan) and type of occupation of household:Japan, 2017 / Volume 1_5-24_Trends in deaths and death rates (per 100,000 population) from malignant neoplasms by sex and site:Japan / Volume 1_5-25_Trends in death rates (per 100,000 population) from malignant neoplasms by sex, age and site:Japan / Volume 1_5-26_Trends in age-adjusted death rates (per 100,000 population) from malignant neoplasms by sex and site:Japan / Volume 1_5-27_Trends in deaths, percent distribution, crude death rates and age-adjusted death rates (per 100,000 population) from cerebrovascular diseases by sex and disease type:Japan / Volume 1_5-28_Trends in deaths, percent distribution, crude death rates and age-adjusted death rates (per 100,000 population) from heart diseases by sex and disease type:Japan / Volume 1_5-29_Trends in deaths and death rates (per 100,000 population) by causes(the list of infectious diseases):Japan / Volume 1_5-30_Trends in deaths and death rates (per 100,000 population) from accidents by external causes:Japan / Volume 1_5-31_Deaths from accidents by age and external causes:Japan, 2017 / Volume 1_5-32_Percent distribution of deaths from accidents by age and external causes:Japan, 2017 / Volume 1_5-33_Trends in deaths and percent distribution from transportation accidents by external causes:Japan / Volume 1_5-34_Deaths and percent distribution from nontransportation accidents by age and place of occurrence:Japan, 2017 / Volume 1_5-35_Deaths and percent distribution from accidents at home by age and external causes:Japan, 2017 / Volume 1_5-36_Trends in deaths and percent distribution from suicide by sex and external causes:Japan / Volume 1_5-37_Trends in maternal deaths and maternal mortality rates (per 100,000 total births) by causes of death:Japan / Volume 1_5-38_Trends in late maternal deaths and late maternal mortality rates (per 100,000 total births) by causes of death:Japan / Volume 1_5-39_Trends in maternal deaths and maternal mortality rates (per 100,000 total births) by each prefecture:Japan / Volume 2_1_Deaths, infant deaths (under 1 year), neonatal deaths (under 4 weeks) and early neonatal deaths (under 1 week), by place of occurrence, for urban/rural residence:Japan, each prefecture and 21 major cities / Volume 2_2_Deaths by sex and month of occurrence:Japan, urban/rural residence, each prefecture and 21 major cities / Volume 2_3_Deaths by sex and age:Japan, each prefecture and 21 major cities / Volume 2_4_Deaths by sex and single years of age:Japan, each prefecture and 21 major cities_(1) Total,0-64years / Volume 2_4_Deaths by sex and single years of age:Japan, each p

Six SNP data sets were generated for different data analyses shown in Table 2 in the main text.

This bar chart displays population (people) by ISO 3 country code using the aggregation sum in Japan. The data is about countries per year.

This bar chart displays rural population (people) by date using the aggregation sum in Japan. The data is about countries per year.

This bar chart displays median age (year) by currency using the aggregation average, weighted by population in Japan. The data is about countries per year.

The G7 countries are facing aging populations in the coming decades. This is especially the case in Italy and Japan, where over ** percent of the population is forecast to be 65 years or older by 2050. By 2050, all G7 countries are predicted to have a higher share of people above 65 years than people between 0 and 19 years. Japan, Italy, as well as Germany already had a higher share of older population than children and youth in 2024.

This bar chart displays population (people) by country full name using the aggregation sum in Japan. The data is about countries per year.

DATASET: Alpha version 2000 and 2010 estimates of numbers of people per grid square, with national totals adjusted to match UN population division estimates (http://esa.un.org/wpp/) and MODIS-derived urban extent change built in. REGION: Asia SPATIAL RESOLUTION: 0.000833333 decimal degrees (approx 100m at the equator) PROJECTION: Geographic, WGS84 UNITS: Estimated persons per grid square MAPPING APPROACH: Land cover based, as described on the website and in: Gaughan AE, Stevens FR, Linard C, Jia P and Tatem AJ, 2013, High resolution population distribution maps for Southeast Asia in 2010 and 2015, PLoS ONE, 8(2): e55882 FORMAT: Geotiff (zipped using 7-zip (open access tool): www.7-zip.org) FILENAMES: Example - VNM00urbchg.tif = Vietnam (VNM) population count map for 2000 (00) adjusted to match UN national estimates and incorporating urban extent and urban population estimates for 2000. DATE OF PRODUCTION: July 2013 Dataset construction details and input data are provided here: www.asiapop.org and here: http://www.plosone.org/article/info:doi/10.1371/journal.pone.0055882