ONS International Migration Statistics Transformation
International migration statistics are vital in aiding our understanding of society. They are a key component of population statistics as well as an area of high public and policy interest. We acknowledge that measuring migration accurately and providing estimates for users in a timely manner is incredibly challenging. ONS’s international migration statistics are currently going through an ambitious transformation programme where ONS is moving away from the International Passenger Survey (IPS) as its main data source and is now working towards an approach based on administrative data sources.
As you are aware, we published our Review of Migration Statistics produced by ONS in March 2022. In this report we set out several recommendations in line with the Code of Practice for Statistics which centred around two main areas:
- improving and broadening user engagement.
- ensuring clear coherent communication of the migration statistics transformation in the context of the wider transformation of population statistics.
Since we published the report, ONS has made substantial progress with the transformation of migration statistics and has communicated this work to the users of international migration statistics throughout the transformation process. ONS’s latest suite of international migration publications, published on 23 November 2023, brought together a range of materials to support users, explaining both the patterns in the data, uncertainty and methodology. This comprehensive suite represents a step forward for ONS’s presentation of its migration statistics.
In February 2023, ONS published a response to update users on its progress against our recommendations. Whilst we recognise that the work on the transformation is ongoing, the report sets our view on ONS’s progress against our recommendations.
It is important that ONS continues its ambitious and innovative work throughout the remaining transformation plans to ensure that its Long-Term International Migration estimates are meeting user needs. Whilst significant progress has been made against our recommendations, ONS should continue to work towards meeting the principles set out in the Code of Practice for Statistics to give users confidence that the published estimates are trustworthy, of high quality and public value. The outstanding recommendations centre around the following four areas:
- Plans for the ongoing review of data sources.
- Developing and publishing measures of uncertainty
- Publishing long-term plans for international migration statistics.
- Publishing a population and migration transformation road map.
ONS has told us that it would like to work towards accredited official statistics status for international migration estimates. We are keen to support ONS in this process in due course. We would like to thank the ONS migration team for its excellent engagement throughout this ongoing review. We will continue to engage with the team to help ensure the transformed statistics are compliant with the Code of Practice for Statistics.
I am copying this letter to Jen Woolford, Director of Population Statistics and Jay Lindop, Deputy Director of the Centre for International Migration.
Director General for Regulation