[4] Koreans are also an officially recognised ethnic minority in other several Continental and East Asian countries, including China, Japan, Kazakhstan, Russia, and Uzbekistan.

Based on linguistic, archaeologic and genetic evidence, their place of origin is located somewhere in Northeast Asia, but its exact pattern of expansion and arrival into the Korean peninsula remain unclear.

Some theories suggest connections to the Altaic region, proposing links with languages and populations in Northern Asia, including Mongolic, Turkic, and Tungusic groups.

[32][33] Whitman (2011) suggests that the Proto-Koreans arrived in the southern part of the Korean Peninsula at around 300 BCE and coexisted with the descendants of the Japonic Mumun cultivators (or assimilated them).

[35] The arrival of early Koreans can be associated with the Bronze Age dagger culture, which expanded from the West Liao River region.

[36] Archaeologic evidence points to a connection between the pottery-making style of the Late Neolithic to Bronze Age cultures in the West Liao River basin and the Korean peninsula.

This analysis, based on 47 alleles across 15 polymorphic loci, demonstrated that Koreans genetically share similarities with Central Asian Mongolian groups.

[41] Modern Koreans can be modeled to be derived primarily from Bronze Age farmers from the West Liao River.

[42] West Liao River farmers of the Bronze Age themselves can be modelled to be derived from the combination of two Ancient Northern East Asian lineages, namely "Neolithic Yellow River farmers" and Ancient Northeast Asians (Amur hunter-gatherers) during the Neolithic period.

It is also suggested that this type of ancestry was introduced into the Japanese gene pool by early Koreanic speakers, during the Kofun period.

[43] WLR_BA ancestry is also associated with the Upper Xiajiadian culture, which in turn can be used as source proxy for Bronze Age and modern Koreans.

[47] One study suggests that modern Koreans may have approximately 85% of their ancestry from Bronze Age populations of the West Liao River region and 15% from settlers associated with Taiwan's Hanben culture.

Additionally, interactions with settlers from southern China (associated with Iron Age Cambodians) are proposed to account for significant genetic variation in modern Koreans.

[59] The mitochondrial DNA markers (mtDNA haplogroups and HVR-I sequences) of Korean populations showed close relationships with Manchurians, Japanese, Mongolians and Northern Chinese but not with Southeast Asians.

The research highlights the complex genetic structure of East Asian populations, shaped by historical migrations and admixture events.

Daily usage of Hanja has been phased out in Korean peninsula other than usage by some South Korean newspapers and media companies when referring to key politicians (e.g. current and former Presidents, leaders of major political parties) or handful of countries (e.g. China, Japan, Canada, United States, United Kingdom) as an abbreviation.

Roman alphabet is the de facto secondary writing system in South Korea especially for loan words and is widely used in day-to-day and official communication.

[81][82][83] Estimating the size, growth rate, sex ratio, and age structure of North Korea's population has been extremely difficult.

Thus, on the basis of remarks made by President Kim Il Sung in 1977 concerning school attendance, the population that year was calculated at 17.2 million persons.

[84] In 1989, the Central Bureau of Statistics released demographic data to the United Nations Population Fund in order to secure the UNFPA's assistance in holding North Korea's first nationwide census since the establishment of the state in 1948.

Although the country lacks trained demographers, accurate data on household registration, migration, and births and deaths are available to North Korean authorities.

According to the United States scholar Nicholas Eberstadt and demographer Brian Ko, vital statistics and personal information on residents are kept by agencies on the ri ("village", the local administrative unit) level in rural areas and the dong ("district" or "block") level in urban areas.

The Korean population in the United States represents a small share of the American economy, but has a disproportionately positive impact.