How much of the UK population was born abroad?
People think about a quarter of the UK was born abroad. The real figure is about one in six, and the number people argue about is often a different one.
What share of people living in the UK are immigrants, what does the public think the share is, and is the public even answering the question the argument is about?
Part 1
What this is about
Every so often, pollsters ask people to guess simple facts about the country. Then they compare the guesses with the official figures. The difference is called the perception gap.
On immigration, people guess too high in every country that has been surveyed. In 2018 the average guess in the UK was that 24% of the population were immigrants. The official figure then was 13%.
The latest figure, from the 2021 Census, is 16%, or about one in six people. That is a lot of people, but far fewer than most guess.
There is a catch. The survey asks how many people living here were born abroad. Political arguments are usually about how many arrive each year. Those are two different numbers, and they get mixed up all the time.
24%
Average public guess for the immigrant share of the population
Ipsos 2018
13%
Official figure the guess was scored against
Ipsos 2018
16%
Latest recorded share
Census 2021
Explainers
Explainer video
Most people think a quarter of the UK was born abroad. It’s lower.
Summary infographic
How much of the UK population was born abroad?
Pollsters ask people to guess how much of the UK population was born abroad. Most guess far too high.
24% — Average public guess (2018) — Ipsos
13% — Official figure at the time — Ipsos
16% — Latest recorded share — Census 2021
The trick: Mixing up “how many live here” and “how many arrived”
One is a total built up over decades and the other covers a single year. Mixing them makes either sound bigger or smaller than it is.
Britain is close to being majority foreign-born.
People guess almost twice the real share.
The survey counts everyone living here, not this year’s arrivals.
People overestimate benefit fraud and unemployment too.
People guess a quarter. The real figure is about one in six. Don’t mix up how many live here with how many arrived.
Part 2
What's being said
Asked what percentage of the UK population are immigrants, the average answer was 24%.
Ipsos, Perils of Perception 2018
The question asks for a share of the total population, so the answer is directly comparable with the official estimate.
Asked what percentage of the population are Muslim, the average answer was 17%.
Ipsos, Perils of Perception 2018
The figure it was scored against was 4%. The 2021 Census for England and Wales records 6.5%.
“Britain is close to being majority foreign-born.”
Paraphrase of a framing in wide circulation
Source neededHow it was used
A framing in wide circulation, used to suggest the country is close to a tipping point.
How it could mislead
It plays on how far people already overestimate the share. Even their high guess, about a quarter, is nowhere near half.
What the figures say
Even people’s overestimate, about a quarter, is nowhere near half. The real share is about one in six. It would have to roughly triple to get close.
“The public is being told a figure far lower than the real one.”
Paraphrase of a framing in wide circulation
Source neededHow it was used
Used to suggest official figures hide the true scale of immigration.
How it could mislead
It turns a real gap the wrong way round. Surveys show people already think the figure is higher than it is.
What the figures say
It’s the other way round. Every survey finds people guess higher than the official figure, not lower.
Part 3
What the figures show
People overestimate lots of things
People guess almost twice the real immigrant share. But they get other things wrong by much more. On benefit fraud, the guess was 34 times too high.
So this isn’t special to immigration. People tend to overestimate things that worry them and that they can’t easily see.
Ipsos, Perils of Perception 2018, except benefit fraud (Ipsos 2013)
Immigrants as a share of population
×1.8
Muslims as a share of population
×4.3
Unemployment rate
×4.5
Benefit spend lost to fraud
×34.3
The real figure has moved
In 2018 people guessed 24% against a real figure of 13%. Since then the real figure has risen to 16%. So the gap has shrunk, even if people’s guesses haven’t changed.
That’s why old comparisons need updating. A 2018 survey tells you about 2018.
Public estimate from Ipsos 2018; official figures as recorded
The other side
- Fewer than people think is still a lot 16% of the population is several million people. Showing that people overestimate the share doesn’t settle whether the level is right.
- People may be describing something real Worries are often about recent arrivals, or change in a particular town. A national total doesn’t capture that.
- The survey is old The main comparison is from 2018. People’s guesses may have changed since.