Japan’s demographic future has long been a subject of fascination and concern. The official numbers, however, come from a single source: the National Institute of Population and Social Security Research, or IPSS. Founded in 1996 under the Ministry of Health, Labour and Welfare, this agency is the government’s designated authority for population projections.
Every five years, it issues a revised set of forecasts that policymakers, economists, and social planners treat as the baseline for the country’s long-term planning.
The Institute and Its Numbers
IPSS released its latest set of projections in 2023. What researchers found is a country headed for a much smaller population. The institute estimates that Japan’s population will fall to 100 million by 2053.
By 2060, it projects a further decline to 87 million. Those numbers represent a steady, decades-long contraction from the current figure, echoing trends that demographers have tracked since the early 2000s.
The working-age population — typically considered those aged 15 to 64 — is expected to shrink even more dramatically. IPSS projects it will drop to 50 million by 2060. That is a critical metric for the country’s economic output and social security system, since it is the pool of potential workers and taxpayers.
Intriguingly, the mechanism behind these projections relies on assumptions about fertility and mortality. The institute’s medium scenario sees the total fertility rate — the average number of children a woman is expected to have over her lifetime — reaching 1.36 by 2030.
That is well below the replacement level of roughly 2.1, meaning the population will continue to age and shrink even if there are no further declines in birth rates. The aging of the population is perhaps the most striking part of the forecast. IPSS projects that by 2065, one in every three Japanese will be aged 65 or older.
That is a demographic structure with profound implications for healthcare, pensions, and elder care.
Beyond the Numbers
IPSS does not stop at projections. The institute also conducts research on social security reform and household behaviour. That work examines how families make decisions about marriage, childbearing, and caring for elderly relatives — factors that feed back into the demographic models.
The science behind the projections is a mix of statistical modelling and survey analysis. The institute runs detailed household surveys to understand attitudes and constraints, then feeds that data into its population models.
The results are updated every five years, meaning the next revision is not due until 2028, assuming the agency stays on schedule. For now, the 2023 projections remain the authoritative guide. They paint a picture of a country that will be smaller, older, and with a significantly smaller workforce.
How Japan adapts to that reality will depend in part on the policy advice that IPSS generates from its social security and household research. The institute’s work, in other words, is not just about counting heads — it is about understanding the forces that shape those counts.
