How does the number of children in Japan differ by age and region?

First, guessYounger groups are smaller, all the way down

Japan's child population is usually reported in three age bands: 0–4, 5–9 and 10–14. Each younger band is smaller than the one above. Read from the bottom up, the line goes down.

This is the shape people mean by "the declining birthrate". It is measured, not predicted — these children have already been born.

What the numbers can sayA count of people, not a judgement about them

The population statistics count how many people of each age live in Japan on a given date. They do not say anything about any one child, family or school.

What they are useful for is planning: how many classrooms a town will need in six years, how many paediatricians, how many school buses.

1. The figures are a snapshot on a specific date — always check which one.
2. Regional shares differ a lot; a national average hides that.
3. A falling count does not mean each child gets less. That depends on decisions, not arithmetic.

Read it carefullyThree questions before you quote a number

Statistics get repeated out of context more than almost anything else. Three questions catch most of the trouble.

1. What exactly was counted — residents, births, or households with children?
2. Whose numbers are these — which ages, which region, which year?
3. When was it collected, and when was it published? Those are different dates.

Talk about itQuestions with more than one answer

If there are fewer children in your town in ten years, what should stay the same and what should change? Which of the things you use every day depends on how many children live nearby? If you moved to a region with a very different share of children, what would you notice first?

SourcesWhere we checked this.

• Population EstimatesStatistics Bureau of Japan — Used for the child population by age band and by prefecture, and for the reference date of each estimate.
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