These Research Outputs are administrative data-based estimates of the population by sex and age for each local authority in England and Wales. These estimates of the size of the population have been produced by linking multiple administrative datasets to produce a Statistical Population Dataset (SPD).

Each year we intend to produce a new set of SPD estimates using:

  • a stable methodology that will remain constant and provide a time series to understand how the method performs over time

  • a new methodology incorporating feedback received, new data that have become available and alternative techniques to produce population statistics

Annually, we aim to publish new SPD estimates of the population for the latest available year and for 2011 to allow comparisons with the latest official population estimates and the 2011 Census estimates.

We've also begun to publish administrative data population estimates down to smaller geographic levels. Analysing data at these levels will help identify areas that have the biggest discrepancy from official population estimates and will help to further refine the methodology and the data sources used.

In addition to the size of the population, we’ve also used SPDs to produce internal migration estimates.

We’re keen to get feedback on these Research Outputs and the methodology used to produce them, including comments on how they might be improved. Please email your feedback to


8 March 2018: Research Outputs: Estimating internal migration in England and Wales, year ending June 2016

20 November 2017: Research Outputs: Estimating the size of the population in England and Wales, 2017 release

17 November 2016: Research outputs estimating the size of the population in England and Wales: 2016 release

22 October 2015 release


These Research Outputs are not official statistics on the population, nor are they used in the underlying methods or assumptions in the production of official statistics. Rather they are published as outputs from research into a methodology different to that currently used in the production of population statistics.

It is important that the information and research presented with each release is read alongside the outputs to aid interpretation and avoid misunderstanding. These outputs must not be reproduced without this disclaimer.