Modelled estimates of annual live births by year ending date. Official birth estimates from ONS are considered very accurate, but the lag between the end of the period covered and the publication of estimates is typically 9-12 months. To gain a more timely indication of birth trends, the GLA Demography team produces modelled estimates of annual births based on counts of infants registered with GP practices. Modelled birth estimates can be produced with the same frequency and latency that NHS Digital publishes patient count data - currently this is monthly and with a lag of 1-2 weeks. The approach used to generate the modelled birth estimates was originally described in this 2016 technical note. The methodology relies on the correlation between the count of persons age 0 (i.e. yet to reach their first birthday) on the patient register and resident in an area with the number of births that have taken place in that area over the preceding year. The data used to create these modelled birth estimates are: Modelled estimates of patient counts by age, sex, and local authority of residence Official estimates of annual live births by local authority of residence A respository of the code used to generate the modelled birth estimates is available on GitHub. The repository's ReadMe provides more information about the methodology used to produce the estimates as well as a summary analysis of their past accuracy. The outputs cover a range of geographies in England. Within London there is variation in how annual births are predicted to have changed since the latest official estimates. The map below shows the percentage change between the latest official births estimates (01 Jan 2024) and the latest GLA modelled births estimate (01 Feb 2025) for London Boroughs. File contents Files containing the outputs from this modelling process are available for download below. The downloads contain official ONS annual births estimates between 01 Jul 1992 and 01 Jan 2024, interpolated estimates at monthly intervals between official estimates, and predictions of annual births up to 01 Feb 2025. Predicted data are given alongside the upper and lower bounds of the 95% prediction interval. The data are given for local authority districts, regions, country, and international territorial levels ITL2 in England. These data are not currently split by sex. The following are example rows to show the format of the csv data file downloads. actual_and_predicted_births.csv gss_code gss_name geography sex date type annual_births interval_lower interval_upper … … … … … … … … … E09000028 Southwark LAD23 persons 2023-12-01 interpolated 3311.5 NA NA E09000028 Southwark LAD23 persons 2024-01-01 actual 3265 NA NA E09000028 Southwark LAD23 persons 2024-02-01 predicted 3301.4 3229.8 3372.9 … … … … … … … … … E09000028 Southwark LAD23 persons 2025-02-01 predicted 3407.8 3322.3 3493.3 birth_gp_ratios.csv gss_code gss_name geography sex date ratio ratio_lower ratio_upper ratio_type gp_count actual_births … … … … … … … … … … … E09000028 Southwark LAD23 persons 2023-12-01 1.111 NA NA interpolated 2981.4 NA E09000028 Southwark LAD23 persons 2024-01-01 1.113 NA NA actual 2932.6 3265 E09000028 Southwark LAD23 persons 2024-02-01 1.112 1.088 1.136 predicted 2968.1 NA … … … … … … … … … … … E09000028 Southwark LAD23 persons 2026-07-01 1.107 1.072 1.142 predicted NA NA The plots.zip download contains png files of plots showing the actual and predicted annual births for each geographic area in the same format as the actual and predicted annual live births plot for London above. There are 3 plots for each different area which give different starting dates for the official estimates backseries to span a total of either 5, 10 or 15 years.

This Excel based tool enables users to query the raw single year of age data so that any age range can easily be calculated without having to carry out often complex, and time consuming formulas that could also be open to human error. Each year the GLA demography team produce sets of population projections. The full raw data by single year of age (SYA) and gender are available as Datastore packages at the links below. How to use the tool Simply select the lower and upper age range for both males and females (starting in cell C3) and the spreadsheet will return the total population for the range. Find out more about GLA population projections on the GLA Demographic Projections page Click here for an archive of population projections from previous years that have since been superseded. 2019-based projections (published November 2020) Central range (upper bound) Central range (lower bound) Low population variant High population variant 2016-based projections (published July 2017) Housing-linked projection incorporating data from the 2016 SHLAA Ward-level projections consistent with the borough housing-led model Ethnic group projections consistent with the borough housing-led model (50MB file)

This Intelligence Unit Update (02-2014) uses ONS population estimates and birth data to examine changes in fertility in London between 2001 and 2011. Update 02-2014 and the accompanying data are both available to download. The Demography Team within the GLA Intelligence Unit publishes a range of population projections which can be accessed via the GLA Demographic Projections Datastore web page.

The GLA is currently developing updated household projection models for use in its 2023-based projections. This page will initially contain raw input data to the projections, with processed data, calculated rates, draft outputs, and links to code being added as development progresses. Inputs: Census estimates of population usually resident population by age, sex, local authority, and residence type. Census estimates of household representative persons by age, sex, local authority, and household type Data from standard Census tables published by ONS have been downloaded from Nomis and republished here. Full metadata for these tables can be found on the relevant pages of the Nomis website. Additional Census tables were commissioned from ONS via the GLA's Census Information Scheme. For further information about the commissioned tables, please contact census.commissiontables@ons.gov.uk

At the April 2023 meeting of the Population Statistics User Group, the GLA Demography team presented an overview of currently available sources of population estimates for the previous decade, namely: The original ONS mid-year population estimates (including rolled-forward estimates for 2021) Experimental outputs from the ONS's Dynamic Population Model The modelled population backseries produced by the GLA to act as inputs to our 2021-based interim population projections The slides from the presentation are published here together with packages of comparison plots for all local authority districts and regions in England to allow users to easily view some of the key differences between the sources for their own areas. The plots also include comparisons of the Dynamic Population Model's provisional 2022 estimates of births with the modelled estimates of recent births produced by the GLA.

The GLA Interim 2021-based population projections (January 2023) comprise both trend-based variant projections and housing-led scenario projections. This dataset contains the detailed methodology documentation for the model and is published alongside the population projections data to assist users in understanding the projections and identifying which set of projections is most appropriate for their needs. The projections themselves can be downloaded here: Population and Household Projections