Page 289 - Invited Paper Session (IPS) - Volume 1

IPS153 Jay L. et al.
The published report provides an update on our GSS Migration statistics
transformation programme and builds on the previous research delivered
through this and the ONS Administrative Data Census project. Previous
publications have set out our progress in linking multiple data sources
together to produce estimates of the size of the population. We have also
carried out targeted work to better understand international migration,
including reports into student migration and work to compare the
International Passenger Survey (IPS) and Home Office visa data for non-EU
migrants.
ONS has long acknowledged that the International Passenger Survey (IPS),
which is currently used to estimate migration to and from the UK, has been
stretched beyond its original purpose and that we need to consider all
available sources to fully understand international migration. At the same time,
our previous research clearly demonstrated that no single source of
information can tell us everything our users want to know, or fully reflect the
complexity of our changing population. Instead it has shown the value that
can be gained from using linked administrative data, while highlighting the
challenges of using this data to measure traditional definitions such as short-
and long-term migration, and usual residence.
A report, published in January 2019, brings together our transformation
work on population and migration, building on our knowledge and
investigating how the administrative data sources now available to ONS can
3
be used, alongside surveys, to improve the way we measure population stocks
and flows in the future.
We are still developing our future system and are in the process of
acquiring the further administrative data sources needed to deliver this – for
example, to address coverage gaps for EU migration. As such, this report does
not directly compare administrative data with our existing IPS-based
migration statistics or make any overall assessments of their statistical quality.
Instead, it provides an update on our approach towards building an
administrative data-based system that will, over time, give us new insights on
the quality of the IPS and our official international migration estimates for the
UK. It also provides evidence of how different administrative sources can help
us to better understand aspects of migration and reveals some of the different
travel patterns that migrants make, such as circular patterns of movement.

3 The Digital Economy Act 2017 provides new opportunities for ONS to access existing data
held by other government departments, for the purpose of producing research and statistics.
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