National Statistical

Emma Rourke explains how ONS is addressing some big questions about a big issue.         

Our  job at the  Office for National Statistics (ONS) is to provide better information to help Britain make better decisions.  At the moment there are few issues more debated and discussed than migration.

People want clear answers to a a few key questions : How many people come to live in the UK from other countries each year? Why?  And how long do they intend to stay?

At the moment, the numbers are mainly estimates from the ONS’s International Passenger Survey (IPS). The survey interviews almost 800,000 passengers each year who pass through airports, sea ports and the Channel Tunnel and provides reliable estimates of the main characteristics of  migration to and from the UK. We’ve just published the latest estimates here.

Increasingly, though, there is demand for information on the impact that migration has on the economy and society: What do they do while they’re here? What services do they use, such as housing? 

We have been working on these and other questions for some time, and today we have also published a report showing how we will develop ways of providing information about migration that meet present-day policy demands and anticipate future questions.

“The real goal is to begin securely and confidentially linking data sources across government to provide a long term solution.”

There are already other sources of data around – the Home Office publishes immigration statistics based on people who require visas to live in the UK, data on asylum and grants of British citizenship. When a foreign national wants to work in the UK, they will apply for a National Insurance Number. Schools, colleges and universities all have databases to capture that information on overseas pupils and students and data are collected from household surveys like the Labour Force Survey (LFS).

Since April 2015, the Home Office has also been collecting additional information as people with non-EEA nationality leave the UK- these are known as ‘Exit Checks’. This information matches the person leaving with the visa they held while in the UK, providing some measure of when people with expired visas leave the UK. It could also be useful to compare this information with emigration estimates from the IPS.

Initially we will look at these other data sources to see what they tell us about the highest priority areas, like whether migrants who come here to study leave after they finish their courses, or what jobs migrants do while they are here. This is just the short-term, though – the real goal is to begin securely and confidentially linking data sources across government to provide a long term solution.

At present, we can only look at these alternative data sources in isolation. The real power of using administrative data could be realised through our ability to securely link different data sources together.  This will provide a much richer combined data source where we can drill deeper into the data to provide more detailed analysis and at smaller levels of geography.

So in the longer term, ONS plans to work with data providers and other government analysts to  build up a much better picture of a migrant’s ‘journey through the UK’ such as when they immigrated, their initial occupation or studies, further skills and occupations or the areas in which they have lived. It could even follow interactions with services such as health care, housing or education. Of course, confidentiality is a priority for ONS – we are not interested in identifying individuals, only how they contribute to the numbers that matter in society.

So will we still need the IPS? Absolutely, because it gives answers to questions that no other data source can. It’s the only way we can find out things like how long people intend to migrate for; their occupation in their previous country; why they are emigrating or who they are accompanying. It achieves the highest response rate of any voluntary survey at around 90% and is conducted by highly trained, dedicated and professional interviewers.

However it can’t give us all the answers, so its future is as part of a UK-wide, timely data system that gives us greater insight into the migrant population.  Our ability to increase our understanding of migrants that come into and out of the UK as well as what they do while they are here, will help us provide the right evidence base for policy decisions and public debate.

The challenge is set – ONS will continue to be instrumental in pushing the frontier of what can be done, working closely with other government agencies and data holders, bringing partners and interested parties onboard to provide the figures the future of the UK requires.

Emma Rourke is Director of Public Policy at ONS