Answers to frequently asked questions about definitions of population projections
- What population is covered by the projections?
- How is a projection different to an estimate?
- Do you produce projections for 1 January? Do you produce projections for 30 April?
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.
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.