A new study out of Japan suggests that unless the country’s restrictive marriage laws change, everyone in the country could eventually end up sharing the same surname. Currently in Japan, married couples are legally required to share a surname, with wives typically taking their husband’s name. However, same-sex marriages are not legal in Japan, and this tradition has led to concerns about the dwindling diversity of Japanese surnames.
The most common surname in Japan is currently Sato, followed by Suzuki and Takahashi. The study predicts that if the current rules around surnames continue, all Japanese people could have the surname Sato by the year 2531. This projection was made by economist Hiroshi Yoshida from Tohoku University, who is calling for legal changes that would allow couples to keep both their last names. Yoshida’s own family name ranks 11th most common in Japan.
One of the main factors that could affect this predicted trend is the declining marriage rate in Japan. In 2023, the number of marriages in Japan declined by nearly 6%, falling below 500,000 for the first time in 90 years. Additionally, divorces were up by 2.6% from the previous year. Yoshida acknowledged that if fewer people marry than expected, the calculation of all Japanese people having the surname Sato by 2531 could be different.
In addition to the declining marriage rate, Japan is also facing a rapidly aging population and declining birth rate. Government figures show that the proportion of Japan’s elderly population, defined as age 65 and above, is at a record high of 29.1%. Japan’s fertility rate is 1.3, far below the 2.1 needed to maintain a stable population. Deaths have been outpacing births in Japan for over a decade, posing a significant challenge for the country’s leaders.
The population crisis in Japan has prompted Prime Minister Fumio Kishida to issue a warning about the country’s ability to maintain social functions in the face of a falling birth rate. The decline in population also raises concerns about the possibility of the Japanese race going extinct over the next millennium. The study suggests that one solution to this issue could be legal changes around surnames to preserve the diversity of Japanese names and potentially mitigate the effects of the declining population.
Similar to Japan, many countries in East Asia have less diverse surnames compared to Western countries. In countries like China, a significant portion of the population shares a small number of surnames. Name extinction is a natural phenomenon known as the Galton-Watson process, which suggests that surnames are likely to be lost or die out over time in patrilineal societies as women take on their husbands’ surnames. This trend highlights the importance of considering legal changes to preserve the diversity of names in Japan and other countries facing similar demographic challenges.
