# R4 | anthropic/claude-opus-5 | run 1

## Prompt

As of the most recent available estimate, what is the population of Japan, and is it increasing or decreasing? Give the figure and year, and cite sources.

## Response

Japan's population is **about 122.93 million** as of July 1, 2026, and it is **decreasing** — down roughly 440,000 people (-0.35%) from a year earlier, according to the government's monthly population estimate. The Statistics Bureau's provisional figure for July 1, 2026 puts the total population at 122.93 million, a year-on-year decline of about 440,000 (-0.35%) [Statistics Bureau Estimates](https://www.stat.go.jp/data/jinsui/new.html).

## Key Figures

| Measure | Figure | Date | Trend |
|---|---|---|---|
| Total population (incl. foreign residents) | ~122.93 million | July 1, 2026 (provisional) | Falling ~0.35%/yr |
| Total population (confirmed estimate) | 122.975 million | Feb 1, 2026 | Falling |
| Japanese nationals only | 119.74 million | Jan 1, 2026 | Falling 0.76%/yr |
| Foreign residents | ~3.74 million | 2026 | Rising ~9.9%/yr |

The confirmed estimate based on the 2020 census showed 122.975 million as of February 1, 2026 [Statistics Bureau](https://www.stat.go.jp/data/jinsui/new.html).

## The Decline Is Structural, Not Cyclical

A separate resident-registry survey released this week marked a symbolic threshold. As of January 1, the population of Japanese residents stood at 119.74 million, down 0.76% from the previous year, per the Ministry of Internal Affairs and Communications — the 17th consecutive year of decline since the 2009 peak [Japan Times](https://www.japantimes.co.jp/news/2026/07/29/japan/japan-population-fall/). This is the first time the Japanese national population has fallen below 120 million in 42 years.

Two offsetting forces explain the gap between the headline total and the Japanese-national figure:

- **Natural decrease** — deaths far exceed births, with roughly 730,000 births against about 1.58 million deaths annually (net loss near 700,000 per year) [Population Clock Analysis](https://worldpopulationclock.net/japan-live-population-clock-by-prefecture/)
- **Immigration partially cushioning it** — the foreign-resident population reached 3.743 million, up 336,000 year on year (+9.87%) [Labor News Summary](https://apj.aidem.co.jp/current/detail/5978.html)

## A Note on Conflicting Numbers

You may encounter figures ranging from 119.7 million to 125.8 million. The differences reflect definitions, not disagreement: Japanese nationals only (~119.7M), total residents including foreigners (~122.9M), and UN-modeled or extrapolated live-counter estimates. Worldometer, using UN Population Division data, estimates 122,427,731 for mid-2026 [Worldometer](https://www.worldometers.info/world-population/japan-population/). The Statistics Bureau figure is the authoritative one.

**Important caveat:** current estimates are still benchmarked to the 2020 census. The Statistics Bureau notes figures will be revised once the basic tabulation of the 2025 Population Census is published, so expect a modest restatement of these numbers.

Would you like the longer-term projections, such as where Japan's population is expected to be by 2050?
