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Answers to frequently asked questions about definitions of population projections

What population is covered by the projections?

Population estimates and projections refer to the usually resident population as at 30 June, whatever their nationality. The usually resident population includes all long-term international migrants who reside in an area for 12 months (or more) according to the standard United Nations definition. Armed forces stationed within an area are included in the population of that area, but visitors and short-term migrants are excluded.

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How is a projection different to an estimate?

An estimate is usually based on available collected data that relates to the time period or point of estimate. A projection takes an estimate at a given point in time and projects how that estimate may change in the future using a set of trends and assumptions. Therefore, a projection will only become true if the trends and assumptions used to produce it were to be realised in the future.

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Do you produce projections for 1 January? Do you produce projections for 30 April?

No. Population estimates and projections produced by ONS all refer to the usually resident population as at 30 June. The components of population change therefore account for changes between 30 June of one year and 30 June of the next year.

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Content from the Office for National Statistics.
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