Dear Sir Ian,

Review of Migration Statistics

Today OSR published our first report reviewing ONS’s transformation of migration statistics in the context of the Code of Practice for Statistics.

Migration statistics are vital in aiding our understanding of society. They are a key component of population statistics as well as being a key area of public and policy interest. However, there are challenges in measuring migration.

ONS has ambitious plans to transform how it measures migration. The previous method based on the International Passenger Survey (IPS) had limitations and so it is good to see ONS looking ahead and developing new more robust approaches.

We have found that ONS is taking a sensible and well thought out approach to its development of data sources and methods. It is effectively collaborating and engaging with academics and experts and publishing regular updates.

We urge the ONS to build on this great work in two main ways:

  • Improve and broaden its engagement with users. We believe that engaging with a broader range of users, including expert and less expert users, will provide the ONS with the challenge and advice to help refine and enhance its approach to measuring migration. It will also help users to become as familiar with these methods as they were with the previous survey-based method.
  • Clear and coherent communication of the migration changes. The migration transformation is taking place in the context of a wider transformation of population statistics and the backdrop of the pandemic. Being clear publicly about the longer-term high-level plan for migration publications, including key decision points, and how these fit within the wider context is essential to keep users engaged with this transformation programme.

Lastly, I want to thank colleagues at ONS for their time and engagement with my team as part of this review and their dedication to the development of migration statistics that serve the public good.

Yours sincerely

Ed Humpherson
Director General for Regulation