National Statistical

We’re working across government to transform the way we produce population and migration statistics, with an aim to put administrative data at the core of our evidence on international migration for the UK and on population in England and Wales. Jay Lindop has more about our latest progress and explains how users are at the heart of our work.

Today we published our latest research showing the progress we’re making on our journey to transform population and migration statistics to give a far deeper and richer picture of migration and its impact on the wider population.

ONS has long acknowledged that the current demands of migration and population statistics are pushing existing sources and methods well beyond their original design. For example, there is now greater demand for information on the contribution and impacts of international migration in the UK, so we are collaborating and sharing data across government to improve the information that is currently available. Our research has been informed by feedback from lots of different people and organisations.

These include central and local government, who use our statistics to inform policy decisions and public services such as how schools and health care are run, as well as academics, researchers and think tanks who use our statistics to provide evidence and insights on population and migration, informing public debate.

Our users are at the heart of what we do, so feedback on what they need our statistics to measure in future, the data sources and methods we should use, and the outputs we need to deliver has been vital in pushing forward our research. Thank you to everyone who got in touch and gave us their views.

What our users told us

We’ve published feedback from users and it shows that we’re heading in the right direction. Our users welcome the move to put administrative data at the core of our statistics – while acknowledging that this is an ambitious programme of work and there are many factors we need to take into account to deliver this.

Users told us they are particularly supportive of our aim to deliver improvements to the accuracy of our migration and population statistics and highlighted a need for more granular data, including on how migrants interact with public services and the labour market. The desire for more detailed local-level data came through strongly in the feedback, alongside support for our plans to explore moving beyond our traditional statistics and definitions such as ‘long term migration’, to better reflect the many ways people move to and from the UK.

Feedback also highlighted the importance of our ongoing work to better understand the coherence across existing survey sources – including the International Passenger Survey (IPS), Annual Population Survey (APS) and Labour Force Survey (LFS) – and a desire for a greater understanding of how patterns align across relevant statistics produced across government.

Our latest research

We’ve made further developments in our approach for producing statistics on the size of the population based on administrative data, outlined here.

Using new data sources, such as income and benefits data, we have refined our methodology so that we include records where there have been recent interactions with administrative systems – for example, a change of address, or registration with a school or GP. This has largely removed the issue of over-coverage – counting too many people as resident in the UK for certain age groups – that we saw in our previous research. There is therefore real potential for this new method to be used in future to provide robust population estimates.

Users also asked about what more we could do to understand irregular migration to and from the UK. We’ve therefore published an article on our work with the Home Office to explore possible measurement approaches.

Alongside this, we’ve built our understanding of the differences in what ONS survey sources – the IPS and APS – tell us about international migration (as set out in our February workplan).

This is an important step in our transformation programme as, in the short-term, it helps explain the patterns we can see in our current official statistics. In the longer-term, this will inform the way we should use the IPS as a leading indicator of migration.

Our latest findings show that while differences in definition between the sources contribute to the different patterns we can see, they do not fully explain them. We have therefore investigated how different country of birth groups contribute to this.

This showed that for many groups the two sources do show similar patterns and the small differences seen are likely to be due to variations in definitions and survey design differences. However, for a few groups, central and eastern European (EU8) countries, East Asia and South Asia, there are larger differences that require further investigation.

Our next steps will therefore be building on the work we have done so far to investigate these patterns further and understand what is driving them, as set out in the workplan. It is too early to say where the best estimate lies but our mission has always been to give the best picture of migration from all sources and we’ll see further progress in the next quarterly migration release.

Our next steps

We’re part way through our transformation journey. However, there is more work we need to do to develop our approach and explore wider data sources that can fill gaps in our evidence base.

As we progress, we will continue to publish further updates on our research and gather feedback along the way. Your feedback is important for shaping our new statistics system and ensuring this continues to meet your needs.

There will be a further update on our work later this year, while next week we’re publishing our research on the impact of migration on the ageing population.