Behaviour shifts and the implications for migration statistics

Image of departures and arrivals sign at Heathrow

Net migration to the UK has been running at record levels. Driven by a rise in people coming for work, increasing numbers of students and world events, the patterns of migration have changed with more arrivals from outside of the EU than in the previous decade. Emma Rourke explains how the ONS is interpreting these behavioural changes, how they feed into the latest data and the implications for other population statistics. 

Over the past two years, net migration has been at the highest level we’ve seen. 

In the year ending June 2023, we estimate it to be 672k, which is higher than 12 months ago but down slightly on our updated estimate for the year ending December 2022. While it’s too early to say if this is the start of a new downward trend, these more recent estimates indicate a slowing of immigration coupled with increasing emigration. 

Before the pandemic, migration was relatively stable, but patterns and behaviours have been shifting considerably since then. These changes are reflected in our recent estimates, which are provisional and supported by assumptions informed by past behaviours and what we are learning about societal changes 

For instance, we’re not only seeing more students arrive, but they’re staying for longer. While historic evidence has shown that over 80% of students typically left within 5 years, analysis of more recent cohorts is suggesting that more are staying for longer and transitioning onto work visas, such as the new graduate visa. We’ve built this change of behaviour into our provisional estimates. 

More dependants – or family members – of people with work and study visas have arrived too.  

The places people are coming from are also changing. Instead of migration to the UK being driven by arrivals from the European Union, we’re now seeing more from further afield, especially China, India and Nigeria. The government’s new immigration system means more people are moving here with their family to fill skilled jobs in health and care sectors for example. 

Patterns of behaviour resulting from urgent international crises are even harder to predict. We’re now seeing fewer Hong Kong British Nationals arriving and even fewer people from Ukraine than a year ago. However, it’s impossible to predict what the future might hold. 

As not enough time has passed to measure if someone has been here 12 months or more – the international definition of a long-term migrant – we do not have complete data for every person included in our most recent migration statistics.   

Updating our migration figures 

As further data becomes available, we will continue to understand more about shifting patterns and behaviours – especially people staying in the UK for longer – and our provisional estimates will be updated with greater statistical certainty. 

For example, we can see in today’s release that our estimates for December 2022 have been revised upwards, however, our net estimate for 17 months ago (June 2022) remained stable as we now have a better understanding of people’s movements over a 12-month period. For the first time in our admin-based migration estimates – which use official records rather than surveys to understand people’s actual behaviours – we publish measures of uncertainty to help users see how our confidence in the estimates grows over time. 

In statistical outputs, we refer to the planned updates resulting from improvements to data or methods as revisions. This approach to revisions enables us to meet a broader set of user needs: those who benefit from an indication of changes as close to the reference period as possible and are willing to accept a higher degree of uncertainty, and those whose need for more accuracy means they will wait for estimates with greater certainty. 

Today we have also released two papers with updated historical population and migration estimates based on Census 2021 data. We go through this process after every census accounting for any drift in our mid-year population estimates, compared with the decennial census. This time the rebasing also includes improvements to our migration statistics based on our new administrative data methods rather than the International Passenger Survey, which we have long said was stretched beyond its original purpose. 

We will continue to develop our proposals for more timely population and migration statistics, avoiding the ten-year wait to rebase or ‘stocktake’ our figures. We will do this on an on-going basis as we get better information about people’s actual behaviours. Today’s statistics, alongside feedback from our recent public consultation  and ongoing research, pave the way for a recommendation next year to Government on the future of population and migration statistics. 

The impact of migration 

Given the high levels of migration to the UK it is perhaps unsurprising that the population of England and Wales has increased at the fastest rate since 1962.  Unlike the baby boom of the early 1960s driving that rise, the increase in 2022 has been largely down to international migration. 

Our latest mid-year estimates give a snapshot of the population as of June 2022, down to local authority level. In December we plan to publish more timely population estimates for mid-year 2023 using our new admin-based population estimates. Again, these provisional estimates will be subject to revision but will give users an early indication of trends.  

In December and throughout today’s releases, we are consistently using the same admin-based migration estimates, to provide greater clarity over the estimates used in our suite of statistical outputs. 

As we move from an old population statistics system, where we predominantly relied on a census, and begin to introduce transformed methods, we have published a population statistics and sources guide to help you navigate how population estimates should be used. We will continue to advise on how our estimates can be used and any limitations.  If you have any feedback on today’s releases, please contact 


Emma Rourke is deputy national statistician

Emma Rourke is Deputy National Statistician