Demographic projections - research outputs
This page contains results of recent projections produced by the GLA that have been designated as research outputs rather than as a full entry in the GLA's annual series of projections.
**Update - 29 May 2026**
An updated set of trend-based projection outputs have been added. These include adjustments to the underlying estimates of population and international migration of children to address recently identified issues with the official series.
**Update - 6 August 2025**
Initial 2024-based trend projection outputs have been added. For more information, please see this blog post.
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The decision not to give a full release to the 2023-based projections was a consequence of problems with official population estimates used as inputs to the models; they are set to be updated later in 2025 once updated estimates are released by ONS.
These outputs were produced in April 2025 as part of the population and pupil projection services that the GLA offers to local authorities in London and are presented here to:
· Indicate the potential scale of impacts that recent updates and revisions to Long-Term International Migration (LTIM) estimates for the UK may have on the final projections.
· Demonstrate the results of a newly introduced methodology for projecting future fertility rates.
· Provide users an opportunity to give feedback on the updated set of projection variants being considered for inclusion in future releases.
· Be used as model inputs during the development of the GLA’s upcoming household projections.
A note providing an overview of the results of and background to these projections will be added in the coming weeks.
The GLA's 2022-based population projections are available here.
2024-based_research_outputs_2026_05_28.zip (217.22 MB)2024-based trend-based population projection research outputs.
The key changes from the outputs published in August 2025 are:
* adjustments to the underlying population estimates to account for identified issues with numbers of children
* choice of past migration periods used for the core variants
This file contains outputs for three 'core' variants:
* 2024_ppt_15yr - Central fertility, Central life expectancy, 15yr migration trend
* 2024_llt_10yr - Low fertility, Low life expectancy, 10yr migration trend
* 2024_hht_15yr - High fertility, High life expectancy, 15yr migration trend
and four additional variants:
* 2024_ppt_5yr - Central fertility, Central life expectancy, 5yr migration trend
* 2024_ppt_10yr - Central fertility, Central life expectancy, 10yr migration trend
* 2024_ppt_20yr - Central fertility, Central life expectancy, 20yr migration trend
* 2024_llt_15yr - Low fertility, Low life expectancy, 15yr migration trend
- 2024-based_research_outputs.zip (696.11 MB)
SUPERSEDED 2026-05-29
2024-based trend-based population projection research outputs.
This file contains outputs for three 'core' projection variants:
2024_ppt_10yr - Central fertility, Central life expectancy, 10yr migration trend
2024_llt_5yr - Low fertility, Low life expectancy, 5yr migration trend
2024_hht_15yr - High fertility, High life expectancy, 15yr migration trend
and four additional variants:
2024_ppt_5yr - Central fertility, Central life expectancy, 5yr migration trend
2024_ppt_15yr - Central fertility, Central life expectancy, 15yr migration trend
2024_llt_10yr - Low fertility, Low life expectancy, 10yr migration trend
2024_hht_10yr - High fertility, High life expectancy, 10yr migration trend
- interim_2023-based_trend_core_variants.zip (94.30 MB)
Interim trend-based population projections for local authority districts in England and Wales (2023 boundaries).
These projections incorporate adjustments made by the GLA to official 2023 estimates of international migration and population such that they are consistent with subsequent revisions to UK Long-Term International Migration data.
This file includes outputs for the three 'core' projection variants:
PP10yr - Central fertility, Central life expectancy, 10yr migration trend
LL5yr - Low fertility, Low life expectancy, 5yr migration trend
HH15yr - High fertility, High life expectancy, 15yr migration trend
- interim_2023-based_housing_led_ward.zip (157.39 MB)
Interim housing-led population projections for electoral wards in London (2022 boundaries).
Due to delays to the publication of official Small Area Population Estimates for mid-2023, ward populations are projected forward from a starting year of 2022 but constrained to the results of trend-based projections with a starting year of 2023. These constraints are applied by ITL level 2 subregion (equivalent to NUTS level 2).
All variants are based on assumptions about future housing development derived from capacity identified in the 2017 London Strategic Housing Land Availability Assessment.
This file includes outputs for the three 'core' projection variants:
Central fertility, Central life expectancy, 10yr migration trend
Low fertility, Low life expectancy, 5yr migration trend
High fertility, High life expectancy, 15yr migration trend
- interim_2023-based_trend_additional_variants.zip (251.43 MB)
Interim trend-based population projections for local authority districts in England and Wales (2023 boundaries).
These projections incorporate adjustments made by the GLA to official 2023 estimates of international migration and population such that they are consistent with subsequent revisions to UK Long-Term International Migration data.
This file includes outputs for a supplementary set of projection variants:
HH10yr - High fertility, High life expectancy, 10yr migration trend
LL10yr - Low fertility, Low life expectancy, 10yr migration trend
HP10yr - High fertility, Central life expectancy, 10yr migration trend
LP10yr - Low fertility, Central life expectancy, 10yr migration trend
PH10yr - Central fertility, High life expectancy, 10yr migration trend
PL10yr - Central fertility, Low life expectancy, 10yr migration trend
PP5yr - Central fertility, Central life expectancy, 5yr migration trend
PP15yr - Central fertility, Central life expectancy, 15yr migration trend
- interim_2023-based_trend_no_ltim_adjustment.zip (93.56 MB)
Interim trend-based population projections for local authority districts in England and Wales (2023 boundaries)
These projections use the 2023 estimates of international migration from the published 2023 mid-year population estimates and are primarily included to allow comparison with projections that include estimates that have been adjusted to fit with revised UK Long-Term International Migration data.
This file includes outputs for the three 'core' projection variants:
PP10yr - Central fertility, Central life expectancy, 10yr migration trend
LL5yr - Low fertility, Low life expectancy, 5yr migration trend
HH15yr - High fertility, High life expectancy, 15yr migration trend