'Immigration policies often just don’t work very well': Interview with migration expert Madeleine Sumption

Why does migration policy cause so much division? And what might help to resolve it?
'The Rwanda deal was very controversial. But I think there will be more of that kind of stuff in the future' Photo: Associated Press/Alamy

By Susan Allott

29 Jul 2026

Dr Madeleine Sumption has a message for civil servants working on migration policy. “I know how difficult it is. I really want to convey some sympathy for the poor people who are charged with delivering this impossible task that we as citizens give them,” she says. 

The word “impossible” pops up a number of times in her conversation with CSW and, indeed, in her new book, What is Immigration Policy For? 

Why does Sumption – who is director of the Migration Observatory at the University of Oxford, chair of the national statistician’s advisory panel on migration statistics and a member of the Migration Advisory Committee – believe it’s impossible to get migration policy right? 

The crux of the problem lies in the contradictions in our expectations, she says. People want managed migration and a strong economy, and they also want to feel good about it – they want the approach our government takes to migration to be fair and humanitarian. These things can’t all be achieved at once. 
This leads to “incoherent or apparently contradictory policies”, she argues in her book. “Immigration policies often just don’t work very well.”

There is also a lack of clarity around the terms we use when we discuss migration policy, Sumption says. A 2023 poll asked respondents in the UK who they had in mind when they used the term “migrant”. Two-thirds of people singled out the smallest group: people seeking asylum. And just over half of respondents thought of people who were migrating permanently, rather than temporarily. “Migration comes in many other forms,” she points out.

And when it comes to deciding which policies are the most ethical, things get even muddier. “As human beings, we tend to be overconfident in our ability to determine what is morally right,” she says.
Sumption’s book is a call for clarity and a clear-headed debate and acts as a tool for achieving this, with section headings that ask fundamental questions such as: “How did we get here?”; “Is immigration policy justifiable?”; and “What is immigration policy trying to achieve?” 

Madeleine Sumption
Madeleine Sumption

Where else does she think we could benefit from more clarity in the debate around migration? For starters, Sumption believes there is a misplaced focus on labour migration in policy debates, which assumes that migration policy is “all about economics”. If it were, she tells CSW, “that would actually be quite easy”. If all migration were labour migration, you could make fairly clear-cut decisions based on who is likely to contribute most to the economy.

“The challenge is that actually, most migration is not from people who are the main applicants on work visas,” she continues. “It’s people who come in for other reasons, particularly if you look at long-term migration.” A lot of migrants are family members of work visa applicants, and refugees. And this is where the “trade-off” begins – with humanitarian goals on the one hand and economic concerns on the other. 

“The types of migration that the government would most like to reduce for economic reasons are the ones that it struggles to control most,” she says. This is because most migrants are unauthorised arrivals seeking asylum, families migrating together or British citizens marrying non-citizens. Ethically, you would want to keep families or married couples together and to be sympathetic to asylum seekers. “But they’re not really fulfilling economic goals,” Sumption says.

Another area where many would like more clarity is in the wording of the 1951 Refugee Convention, which underpins global policy around refugees, stating that people with a “well-founded fear of being persecuted” should not have to return to a country where they may face persecution. The convention does not require refugees to arrive through legal routes or to claim refugee status in the first safe country they reach. It also does not set out how the settlement of refugees should be shared out between countries. 

The result is that high-income countries such as the UK attract more refugees than lower-income countries. A lot of resource then goes into the process of establishing whether an asylum seeker meets the definition of “refugee”, and therefore has protection from removal, or not.

Sumption is not convinced there is scope for amending the convention, either for clarity or for greater perceived fairness to those shouldering the highest costs. She makes the point that “the lack of agreement on who’s responsible is the source of tension, and the reason that this whole thing has been difficult, but it’s also the thing that enabled that global agreement to happen and to last for so many decades”.

“The Rwanda deal was very controversial. But I think there will be more of that kind of stuff in the future”

Expanding on this point, she says that “any formula where you divided out refugees among countries would lead to a country like the UK taking dramatically more refugees than it currently does. And the UK just doesn’t have an incentive to do it”.

She thinks there is potentially more scope for solutions that involve countries like the UK contributing financially instead. The cost of resettling a refugee in the UK is “actually pretty high”, she explains. “That amount of money goes a lot further in developing countries. You could imagine setups where higher-income countries effectively finance the hosting of refugees in developing countries, although these sorts of multilateral actions are very difficult.”

Reducing the number of refugees might need to happen in controversial ways, Sumption says: “The Rwanda deal was effectively paying money to Rwanda to host refugees there, and it was very controversial. But I think there will be more of that kind of stuff in the future.”

In her book, Sumption describes one element of migration policy as the “least sexy of all”. That element is the collection of data and the need to address the distinct lack of it in certain key areas. CSW begs to differ on the sexiness of data – much to Sumption’s delight. “I could talk about this for hours,” she says. 

There is a lack of population data broken down by immigration status and by nationality, for starters. “It’s five years since the England, Wales and Northern Ireland census and there’s been a lot of migration since then so the census data aren’t very relevant, and we currently don’t really know how many people from each country of origin are in the UK and what their status is”.

And we will never have a perfect picture of the number of people who are here without permission, she says. “But even the people who are here with permission, who have gone through all of the relevant processes, it’s just very difficult to get a clear picture of that.”

Book: What is immigration policy for? by Madeleine Symption

Good data matters, Sumption says, because officials need to understand the impacts of the policies they are implementing to know whether they have been successful and where they need to be adapted. 

“So, for example, there’s a lot of debate now about the benefits system and how and when migrants should get access to benefits,” she says. “It’s really challenging to understand the impacts, because although we have some data on who’s claiming benefits, we don’t have a good denominator for any of that. So it’s very hard, actually, to calculate rates of benefit claiming in different groups.”

There has been “a little bit of movement” towards improving this, she adds. But it remains difficult to understand the baseline number of people in the populations of migrants that claimants come from, what their immigration status is, and which policy they entered the country under – for example, whether they came in on a student visa or as a family member of a citizen.

Crime is another area where the data is lacking. “It looks like asylum seekers are probably over-represented among people in the criminal justice system, but we don’t have the denominator for that to work out how rates of crime vary depending on people’s status in the UK.” 

Sumption also points out that the Office for Budget Responsibility “really needs good data” to forecast the impacts of migration on public finances. For example: “How much are migrants earning? What are the employment rates? How does that depend on different policies and so forth? A lot of that is missing.” The data relating to migrants moving through mainstream government systems is “reasonably good”, according to Sumption – for example, if someone arrives on a work visa then marries a British citizen, sticking to legal parameters.

"It’s going to be a huge problem if this or a future government wants to reform ECHR or pull out. We don’t have enough information to understand the impacts of that”

“Where we don’t have that same picture is outside of those mainstream routes. There are actually quite a lot of people who either who fall out of those mainstream routes, or arrive without permission and then get regularised,” she says. She gives an example of someone who overstays their visa – they might remain in the country illegally but become legalised later on because they have a human rights claim. “There are all of these different systems,” she says. “Because the system’s not connected up, we really don’t have a good sense of the links between them. And this really matters for developing policy, right?”

The big policy debate around migration at the moment relates to the appeals system. “We know very little” in terms of the nature of those appeals or the immigration history of the people in the system, according to Sumption. But the second big policy debate, which she believes is only going to grow as an issue, is around the European Court of Human Rights. “We do not know enough about the data on how ECHR and all of these different human rights mechanisms are affecting migration,” Sumption says. “And it’s going to be a huge problem if this or a future government wants to reform ECHR or pull out. At the present, we just don’t have enough information to really understand the impacts of that.”

In her book, Sumption concludes that although there is “no single right answer, there are some things that perhaps we can all agree on”. One of these, she suggests, is the importance of “good old-fashioned competence”. She points out that “inattention to the dull business of competently running the asylum system was a major factor behind the spiralling asylum backlog in the UK between 2018 and 2022”. 

“Backlogs cause all sorts of problems,” she tells CSW. For example, when someone’s asylum status is not determined, they are usually not permitted to work. “If someone is expected to get a job and become self-sufficient and support themselves here, it’s not good for their integration to have this period of uncertainty.”

Similarly, if someone is ultimately going to be returned to their country of origin, “the longer they stay here, the more difficult that becomes”, Sumption says. “The more likely it is that the government loses track of them or perhaps, if they wait a really long time, they may then start to become eligible to remain on human rights grounds, such as family life. Ultimately, it’s just a very inefficient and expensive way of running the system.”

Now that the asylum backlog has started to clear, there is a backlog in the appeals system – something that Sumption points out should have been predictable: “A lot more people being refused asylum means a lot more people appealing.”  And while “good old-fashioned competence” might not be a winning election message, it can offset huge problems that matter to the public. “The appeals backlog is spiralling and that’s the reason the government is struggling to meet its pledge to end the use of asylum hotels,” Sumption says. 

“Migration is not monolithic,” she says, when asked what key message she would most like the readers of her book to take away. “Sometimes there’s an assumption that more migration is economically beneficial and less is economically damaging, for example. And that’s just not true, based on the evidence.” Understanding who is migrating is more important than understanding the number of migrants coming into the country, she continues. “Some people will have a negative impact on public finances and some will have a positive impact. You absolutely have to know who is migrating and not just treat everyone as interchangeable.”

Her plea to policymakers is to be wary of proposals that over-simplify the problem. “It’s not only politicians who are susceptible to the charms of symbolic policies – by which I mean policies that sound like they might be a good idea, but aren’t actually going to achieve their desired effects,” she says. 

Can she give an example? “I mean, investor visas, which had a lot of support across government, I think are a classic example,” she says, describing the policy as “the biggest discrepancy I’ve ever seen between what it was supposed to do and what it actually did”. Investor visas were envisaged as a way of bringing “exciting, dynamic people like Richard Branson” into the UK to build their business. 

“And the thing is that these overseas Richard Bransons are very happy making a lot of money overseas," Sumption says." They don’t want to move here. Their wives and children do want to move here. And so the investor visa ended up being a sort of leisure visa for Russian housewives who wanted to send their kids to private school. And I think it was very clear that it was not the original goal of the policy.”

She thinks that sometimes, especially outside of the Home Office, there is a tendency to look for an immigration solution without checking whether there is a genuine problem to be addressed. “The solution can come before the problem,” she says. “And you might think that’s harmless, but these things take time and money to set up and run.”

Given how much tension there is around migration policy, and how polarised the public is on the subject, Sumption’s final request is for robust evidence – for policies to be properly evaluated.

“Ministers want it to be implemented and so there isn’t always the time or the resources dedicated to the analytical side of things,” she says. “The analytical people aren’t necessarily in the room when those decisions are taken.”

The evidence would make a difference, she says, in an area where it sometimes seems that solutions are not forthcoming. At least then it might be possible to have an honest, informed debate. 

What is Immigration Policy For? is published by Bristol University Press

Share this page