Approximately **** million people in Japan were estimated to be within the age group 65 and over in 2024. This number was projected to ******** until 2040 and then ******* to about **** million by 2120.

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.

In 2023, there were around *** live births per 1,000 inhabitants in Japan, down from about *** in the previous year. The total number of live births in the nation amounted to approximately ******* in 2023. Japan’s super aging society Directly after the end of WWII, the live birth rate in Japan was over ** per 1,000 of population. The rate has constantly dropped in the last decades after the second baby boom (between 1971 and 1974). Meanwhile, the life expectancy of the Japanese people has increased, reaching about **** years for women and **** years for men in 2022. Due to the combination of both factors, Japan has developed into one of the most rapidly aging societies in the world. Almost ** percent of Japan’s population is currently aged 65 years and older, falling into the “super-aged nation” defined by international institutions and organizations.  Decreasing number of marriages In Japan, the number of births outside of marriage is small. The Japanese government, therefore, considers the decreasing number of marriages as the driving factor behind the country’s fertility decline. As of 2023, the number of marriages per 1,000 Japanese citizens was ***, less than half compared to that in the early *****. The average age of first marriage has also risen for both men and women. This trend can be partially attributed to the increasing number of employed and therefore financially and socially independent women in the past two decades. The employment rate of women in Japan exceeded ** percent for the first time in history in ****.

As of 2024, the total population in Japan was estimated to be approximately ********************. The projection for 2100 indicated an almost ** percent decrease in population to around **** million people.

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)

In 2023, the annual population growth in Japan stood at -0.49 percent. Between 1961 and 2023, the figure dropped by 1.39 percentage points, though the decline followed an uneven course rather than a steady trajectory.

Shrinking cities due to low birthrates and aging populations represent a significant urban planning issue. The research question of this study is: which economic, social, and educational factors affect population decline in Japanese shrinking cities? By modeling shrinking cities using the case of Japanese cities, this study aims to clarify the indicators that affect the population change rate. The study employed Bayesian network analysis, a machine learning technique, using a dataset of economic, social, and educational indicators. In conclusion, this study demonstrates that social and educational indicators affect the population decline rate. Surprisingly, the impact of educational indicators is more substantial than that of economic indicators such as the financial strength index. Considering the limitations in fiscal expenditures, increasing investment in education might help solve the problem of shrinking cities because of low birthrates and aging populations. The results provide essential insights and can function as a planning support system.

Column names are based on the text and Table 1. Period IDs are as follows: 1: 1976–1987; 2: 1987–1997; 3: 1997–2006; 4: 2006–2009. (CSV)

Geographical and social variables explaining farmland abandonment in each period.

Okinotorishima Island, an isolated remote table reef island in the southernmost territory of Japan, provides an excellent site to examine the effect of only global stress, as there are no local human stresses present. Yamamoto et al. (2023) established 17 fixed quadrats (1×1 meter) on 9 knolls in the shallow lagoon of Okinotorishima Island, and observed coral population every May from 2006 to 2015. This dataset compiles data on coverage and number of colonies of Acropora and co-occurring corals published in Yamamoto et al. (2023). Yamamoto, H., Kawasaki, T., Tamura, K., Kanyama, T. Hosono, T., Fudo, M., Omori, M., Kayanne, H.: Decline in the Acropora population due to repeated moderate disturbances in Okinotorishima Island, Japan. Glaxea: Jour. Coral Reef Studies 25: 18-30 (2023). doi: 10.3755/galaxea.G26-3

Posterior distribution means and 95% credible intervals for the model intercept and the coefficients of predictors for each period.

In 1800, the population of Japan was just over 30 million, a figure which would grow by just two million in the first half of the 19th century. However, with the fall of the Tokugawa shogunate and the restoration of the emperor in the Meiji Restoration of 1868, Japan would begin transforming from an isolated feudal island, to a modernized empire built on Western models. The Meiji period would see a rapid rise in the population of Japan, as industrialization and advancements in healthcare lead to a significant reduction in child mortality rates, while the creation overseas colonies would lead to a strong economic boom. However, this growth would slow beginning in 1937, as Japan entered a prolonged war with the Republic of China, which later grew into a major theater of the Second World War. The war was eventually brought to Japan's home front, with the escalation of Allied air raids on Japanese urban centers from 1944 onwards (Tokyo was the most-bombed city of the Second World War). By the war's end in 1945 and the subsequent occupation of the island by the Allied military, Japan had suffered over two and a half million military fatalities, and over one million civilian deaths.

The population figures of Japan were quick to recover, as the post-war “economic miracle” would see an unprecedented expansion of the Japanese economy, and would lead to the country becoming one of the first fully industrialized nations in East Asia. As living standards rose, the population of Japan would increase from 77 million in 1945, to over 127 million by the end of the century. However, growth would begin to slow in the late 1980s, as birth rates and migration rates fell, and Japan eventually grew to have one of the oldest populations in the world. The population would peak in 2008 at just over 128 million, but has consistently fallen each year since then, as the fertility rate of the country remains below replacement level (despite government initiatives to counter this) and the country's immigrant population remains relatively stable. The population of Japan is expected to continue its decline in the coming years, and in 2020, it is estimated that approximately 126 million people inhabit the island country.

Semi-natural grassland areas expanded worldwide several thousand years ago following an increase in anthropogenic activities. However, semi-natural grassland habitat areas have been declining in recent decades due to changes in landuse, which have caused a loss of grassland biodiversity. Reconstructing historical and recent demographic changes in semi-natural grassland species will help clarify the factors affecting their population decline. Here, we quantified past and recent demographic histories of Melitaea ambigua (Lepidoptera; Nymphalidae), an endangered grassland butterfly species in Japan. We examined changes in demography over the past 10,000 years based on 1,378 bp of mitochondrial COI gene. We then examined changes in its genetic diversity and structure during the last 30 years using nine microsatellite DNA markers. The effective population size of M. ambigua increased about 3,000 to 6,000 years ago. In contrast, the genetic diversity and effective population sizes of many populations significantly declined from the 1980s to 2010s, which is consistent with a recent decline in the species population size. Our data suggest that the M. ambigua demography can be traced to changes in area covered by semi-natural grasslands throughout the Holocene.

Throughout the Common Era, Japan's population saw relatively steady growth between each century. Failed invasions and distance from Asia's mainland meant that Japan was unaffected by many pandemics, primarily bubonic plague, therefore its development was not drastically impeded in the same way as areas such as China or Europe. Additionally, religious practices meant that hygiene was prioritized much more in Japan than in other regions, and dietary customs saw lower rates of meat consumption and regular boiling of water in meals or tea; both of these factors contributed to lower rates of infection for many parasitic or water-borne diseases. Fewer international conflicts and domestic stability also saw lower mortality in this regard, and Japan was an considered an outlier by Asian standards, as some shifting trends associated with the demographic transition (such as lower child mortality and fertility) began taking place in the 17th century; much earlier time than anywhere else in the world. Yet the most significant changes came in the 20th century, as Japan's advanced healthcare and sanitation systems saw drastic reductions in mortality. Challenges Japan's isolation meant that, when pandemics did arrive, the population had less protection and viruses could have higher mortality rates; smallpox has been cited as the deadliest of these pandemics, although increased international contact in the late 19th century brought new viruses, and population growth slowed. Earlier isolation also meant that crop failure or food shortages could leave large sections of the population vulnerable, and, as mentioned, the Japanese diet contained relatively little meat, therefore there was a higher reliance on crops and vegetables. It is believed that the shortage of arable land and the acidity of the soil due to volcanic activity meant that agriculture was more challenging in Japan than on the Asian mainland. For most of history, paddy fields were the most efficient source of food production in Japan, but the challenging nature of this form of agriculture and changes in employment trends gradually led to an increased reliance in imported crops. Post-Sakoku Japan Distance from the Asian mainland was not the only reason for Japan's isolation; from 1603 to 1853, under the Tokugawa shogunate, international trade was restricted, migration abroad was forbidden, and most foreign interaction was centered around Nagasaki. American neo-imperialism then forced Japan to open trade with the west, and Japan became an imperial power by the early-1900s. Japanese expansion began with a series of military victories against China and Russia at the turn of the century, and the annexation of Taiwan, Korea, and Manchuria by the 1930s, before things escalated further during its invasion of China and the Second World War. Despite its involvement in so many wars, the majority of conflicts involving Japan were overseas, therefore civilian casualties were much lower than those suffered by other Asian countries during this time. After Japan's defeat in 1945, its imperial ambitions were abandoned, it developed strong economic ties with the West, and had the fastest economic growth of any industrial country in the post-WWII period. Today, Japan is one of the most demographically advanced countries in the world, with the highest life expectancy in most years. However, its population has been in a steady decline for over a decade, and low fertility and an over-aged society are considered some of the biggest challenges to Japanese society today.

Demographic characteristics of callers under 20 years of age (N = 24,333).

This comparative project (UK, Japan, Germany, US & New Zealand) examined how governments prepare citizens for collapse in the Critical National Infrastructure (CNI); how they model collapse and population response; case studies of CNI collapse (with particular reference to health and education) and the globalisation of CNI policy. It was funded by the Economic and Social Research Council under grant reference ES/K000233/1. It considered:- 1. How is the critical infrastructure defined and operationalised in different national contexts? How is population response defined, modelled and refined in the light of crisis? 2. What are the most important comparative differences between countries with regard to differences in mass population response to critical infrastructure collapse? 3. To what degree are factors such as differences in national levels of trust, degrees of educational or income inequality, social capital or welfare system differences particularly in the education and health systems significant in understanding differential population response to critical infrastructure collapse? 4. How can a comparative understanding of mass population response to critical infrastructure collapse help us to prepare for future crisis? Research design and methodology Methodologically the study was focused on national systems in developed countries. The focus was on different 'welfare regimes' being broadly liberal market economies (the UK, US and New Zealand) and broadly centralised market economies (Germany and Japan). The data arising from the project was of various types including interviews, focus groups, archival data and documentary evidence. The 'National Infrastructure' is seldom out of the news. Although the infrastructure is not always easy to define it includes things such as utilities (water, energy, gas), transportation systems and communications. We often hear about real or perceived threats to the infrastructure. In this research we will construct 'timelines' of infrastructure protection policy and mass population response to see exactly how and why policy changes in countries over time. We will select a range of countries to represent different political and social factors (US, UK, New Zealand, Japan and Germany). The analysis of these timelines will suggest why national infrastructure policy changes over time. We will then test our results using case studies of actual disasters and expert groups of policy makers across countries. Ultimately this will help us to understand national infrastructure protection changes over time, what drives such changes and the different ways in which countries prepare themselves for infrastructure threats. In addition, through a series of 'leadership activities' the research will bring together researchers in different academic disciplines and people from the public, private and third sectors. The methodology used was to enable an understanding of how countries had developed strategies of mass population response to critical infrastructure failure. The methods were:- 1. Archival research using data in country archives from 1945 to the present day on population response (planned and actual to disasters) 2. Focus groups and interviews with selected experts to enable us to further understand the data in (1). 3. Case studies of actual infrastructure failures - summary notes were prepared from documentary evidence on disasters.

Small abalone (Haliotis diversicolor) is a commercially valuable species for both fisheries and aquaculture. The production of annual farmed small abalone in Taiwan, once the highest in the world, has dramatically decreased in the past 15 years, and currently, the industry is close to collapse. Understanding the genetic diversity of small abalone and developing stock identification methods will be useful for genetic breeding, restoring collapsed stocks, managing stocks, and preventing illegal trade. We investigated 307 cultured and wild individuals from Taiwan, Japan, and Bali Island (Indonesia) by using the mitochondrial cytochrome c oxidase subunit I (COI) gene. Network analysis of mtDNA COI gene sequences revealed that the individuals collected from Taiwan, Japan, and Indonesia could be identified, and showed significant genetic divergence. In addition, the Indonesian population (Haliotis diversicolor squamata) was significantly different from the other populations and might need to be considered a separate species. We discovered a single nucleotide polymorphism marker in the mtDNA COI gene that can be used to distinguish the Taiwan population from the Japan population. We also developed a polymerase chain reaction-restriction fragment length polymorphism method for rapid detection. Furthermore, we could identify the cultured stocks, wild population, and hybrid stocks by using 6 microsatellites and amplified fragment length polymorphism. This study contributes useful tools for stock identification and the production of high-disease resistant small abalone strains (Japan × Taiwan or Taiwan × Japan). Efforts should be made to avoid unintentional random genetic mixing of the Taiwan population with the Japan population and subsequent breakdown of population differentiation, which impair local adaptation of the Taiwan wild population. Molecular markers revealed a split between the Taiwan and Japan populations, and the existence of a possible barrier to the free dispersal of small abalone is discussed.

In 2023, the total fertility rate in children per woman in Japan stood at 1.2. Between 1960 and 2023, the figure dropped by 0.8, though the decline followed an uneven course rather than a steady trajectory.

Of the G7 countries, Canada, the United Kingdom, and the United States were forecast to have a constant population ******** until 2050. In Japan, Germany, and Italy, the population is forecast to constantly ******* due to aging populations and falling fertility rates. In France, the population was first expected to decline by 2048.

For most of the past two centuries, falling birth rates have been associated with societal progress. During the demographic transition, where pre-industrial societies modernize in terms of fertility and mortality, falling death rates, especially among infants and children, are the first major change. In response, as more children survive into adulthood, women have fewer children as the need to compensate for child mortality declines. This transition has happened at different times across the world and is an ongoing process, with early industrial countries being the first to transition, and Sub-Saharan African countries being the most recent to do so. Additionally, some Asian countries (particularly China through government policy) have gone through their demographic transitions at a much faster pace than those deemed more developed. Today, in countries such as Japan, Italy, and Germany, birth rates have fallen well below death rates; this is no longer considered a positive demographic trend, as it leads to natural population decline, and may create an over-aged population that could place a burden on healthcare systems.