By Jess Bowie

25 Oct 2023

Jess Bowie meets the founding director of the Behavioural Insights Team


Professor David Halpern is a former senior civil servant and founding director of the Behavioural Insights Team. He was CEO of the BIT from its launch in 2010 until 2023, when he took up his current role as the team’s president.

Between 2001 and 2007 Halpern was the chief analyst at the Prime Minister’s Strategy Unit and, from 2008-2010, was a founding director of the Institute for Government. He was also What Works national adviser from 2013-2022 – a role which saw him lead efforts to improve the use of evidence across the UK government.


The Civil Service Club is in Great Scotland Yard, between Whitehall and Northumberland Avenue. It provides a restaurant for members and their guests in comfortable, friendly surroundings.

We discussed

Surprises moving from academia to government
I couldn’t believe the lack of access to empirical sources. I would ask what literature colleagues were using and they didn’t have access to any journals. A lot of departments still don’t today. They would be writing a note to the prime minister to recommend what to do to reduce crime, say, but wouldn’t have access to the best evidence, to the primaries. That was pretty shocking. 

Where power is located 
One of the most enduring lessons, which I still remind researchers about, is that everybody thinks someone else has got the power. It’s striking in a place like Whitehall. There’s a presumption of  “if only I was the prime minister, I could finally get this done”, but even prime ministers are exasperated about what they can’t do. It’s frustrating but also empowering; in a sense, [power] is not somewhere else. Anybody in the system – including the civil service – has power in some appropriately bound way. All you need to think is: “What is it I could do where I am now that could make a difference?” 

The relationship between prime ministers’ knowledge and their power
The longer you are prime minister, the more confident and knowledgeable you become in the post but, correspondingly, your power edges away. By 2005, 2006 and 2007, Blair was incredibly knowledgeable, and had been doing the role for a very long time. There were many areas where he knew as much as his policy advisers. But he had set a date for his departure and his power was ebbing away. It’s a really important question: how can you accelerate that learning curve and bring it forward? You don’t want to wait five or 10 years to get there.

Learning from predecessors
We did a big piece of work before the transition from Blair to Brown – on what worked and what you might want to refresh. It was this big reset moment and you don’t get an opportunity like that very often. Well, the truth is that Gordon wasn’t particularly interested [in our findings]. But the point is that you really should lean into learning from your predecessors. However you feel about them, you should still want to learn from them.

Working for governments of different parties
Transitions of administrations are extraordinarily exciting, and they don’t happen very often. They bring in this energising force because new perspectives flow. But there are also very striking continuities. For example, as part of that work we did before the transition from Blair to Brown, we’d done an away day for the cabinet at Lancaster House about a whole range of issues and then, in the same room in 2010 with the new [Cameron-led] administration, we had another big conversation with ministers present talking about public service reform. It was a weird moment – in many ways it felt like a continuation of the same conversation. 

Personal successes in government 
Ah, but how would you know if something was successful? It’s a dirty secret that we spend a trillion a year in Britain and we don’t know what works. So I think my answer would be bringing in practices and helping institutions get better at answering that question: does it work? Was it successful?

“If we’re spending a trillion a year, we should be waking up at night thinking: ‘Was that the best thing we could have done with that money?’”

A recent, clear expression of that is the Evaluation Task Force. We now have a big chunk of the British government that’s serious about evaluating success. And of course there are the What Works centres, some of which are genuinely world-class. And all of this links to the Behavioural Insights Team, too: you could say the biggest thing we did with the BIT was act as a Trojan horse for bringing very hard empirical methods into the heart of government. I think that is really significant – and revolutionary in its own way.

Favourite nudge he’s been involved with
That’s like asking: “Who’s your favourite child?” I would put the work we did with the Department for Work and Pensions in jobcentres near the top. Over the last 40 years, from the Nordic countries through the US and the UK, active welfare policy has all been premised on acting as a kind of policeman, asking unemployed people: “What jobs did you look at last week?” and making them prove they’re looking for work. But along with JP Marks – now permanent secretary of the Scottish Government, but back then a grade five – we tested an alternative, training jobcentre advisers to ask people what they were going to do next week to look for work. We wanted to know if it got people back to work faster and it did – by a very significant amount. 

We’ve since helped lots of other countries replicate that across Eastern Europe, and in Singapore and Australia. It’s really robust and it’s just a lovely intervention, because it gets people into work faster while saving taxpayers a very large sum. It’s also a more human interaction – it puts the “adviser” back into “personal adviser” and, as a result, we noticed improvements in the work satisfaction of jobcentre staff, too. 

What else he’s proud of
An obvious one – which is different because it’s a policy intervention – would be the sugar levy. That was a very long argument. We first proposed it, and worked with [late cabinet secretary and head of the civil service] Jeremy Heywood on it before the 2015 election. It was complicated and controversial to get through, but we are now close to halving sugar in fizzy drinks, and the total market share in fizzy drinks has increased at the same time. It crossed the rubicon, because people were terrified of this kind of instrument, but we showed it could be effective. 

My team helped to reverse the government’s position on vaping, to ensure it was available in the UK. I don’t have regrets about the origins of the policy – it was a really good, forward-thinking policy. E-cigarettes have saved an estimated one million years of life in the UK and they are 95% better from a health perspective than smoking.

But because there wasn’t tight enough regulation to ensure that they weren’t available to kids, there has been a creeping undermining of the policy, and there is now doubt in people’s minds, including many clinicians’, that e-cigarettes are dangerous – or worse than smoking.

Vaping was always intended as a tool to help smokers quit, and what’s happened since [with its uptake by young people] shows the importance of following through. Even if the starting policy is right, the detail matters and you have to keep working on it, and refining the regulations over time as the market evolves.

Bullseyes in urinals to help men aim and reduce “spillage” 
Richard Thaler [one of the founding fathers of behavioural economics and co-author of the seminal 2008 book Nudge] always loved that one. It’s never clear if it was actually subject to a proper controlled trial. If you ever bump into Richard you can ask: how did they know? What was the exact measurement of the spray? I never quite got a straight answer on that…

Knife throwing
I once said that I liked knife-throwing with my teenage sons and that quote has followed me around. I haven’t done much recently, but we still have the knife-throwing board up in the garden. It’s quite a zen thing to do, though my wife wants me to take it down. My sons are grown up now. One is just finishing his PhD on the origins of the genetic code, and the other has completed his masters, which is on lots of worthy things to make the world better. They probably think they’re branching out from what I do, but we’re all caught by our own origins to some extent, aren’t we?

How he unwinds
Who doesn’t love Ted Lasso? I feel like watching it makes me a better person. I do read a bit, although I leave fiction for holidays. At the moment, I’m reading The Narrow Corridor [by Daron Acemoglu and James A. Robinson], which is a superb piece of work. I still find the field interesting. Joe Henrich’s The Weirdest People in the World is another brilliant book. I definitely don’t do yoga, though. I’m too impatient. 

What makes a good minister
A clarity of purpose, combined with an open mind and use of evidence. One of those key flashbulb moments was when Nick Clegg was around and there was a disagreement between two departments about a particular policy issue, and Nick said, “So neither of you know what is going to work? Why don’t we run one of those, what do you call it, randomised control trials?” 

“Perm secs don’t get to that level without being very smart, but they will also have gone through a long arc of a system that often squeezes out their original passion”

 What makes a good permanent secretary
Permanent secretaries are all incredibly impressive, and all very different. They don’t get to that level without being very smart, but they will also have gone through a long arc of a system that often squeezes out their original passion and policy purpose. The ones who are great are those who have retained a sense of being able to do something for good. They’re passionate and interested in trying to find the right answer, and using their power and responsibility to have an impact in the role. For those of us who worked with Jeremy Heywood, we knew he wasn’t just extraordinary and a brilliant mind but was palpably passionate. 

The risks of underusing behavioural insights
A danger for behaviour insights is getting boxed into quite a small space – namely that it’s just about comms. “I’m writing this letter. Can you help make it a bit better?” Yes, we can, but applications for insights should expand into market design or fundamental policy design, too. If you’ve been boxed into helping with communications, that’s a very narrow take on the discipline and its application. In the academic world, “nudge” has been interpreted quite narrowly. Well, if you define them narrowly, then they are narrow in their impact, but that’s not what we do. We’re interested in watching the factors that affect behaviour, including taxes, regulations and lots of other things. It’s a real puzzle to work out what’s effective – but it’s part of the policy challenge in almost every domain.

Nudge sceptics
There are two seemingly paradoxical critiques of behavioural insights, particularly nudges. There’s this libertarian perspective which sees them as messing in people’s heads in a nanny-state way. On the flipside, they’re seen as a fig leaf, and a substitute for doing proper regulation or tax. They’re either frighteningly powerful, or too weedy and weak. Can it be both those things?

Behavioural forces at the collective level
Choice enhancing language is often used at the individual level, but a lot of these behavioural forces are operating at the collective level. Why not ask the public what they want to do, not least because the key enforcers of policies are often the public themselves? 

Take the canonical example of the chips versus the salad in a canteen. What happens if we show the public how the position of different dishes in a canteen affects what they choose to eat, and then ask them what they would prefer? Why not put evidence to the public and ask them what they want to do? The logic [of choice-enhancing language] should apply to the collective: can we not empower the public to make decisions after providing them with the evidence?

Frustration at the pace of change
The civil service isn’t good enough at distinguishing and weighting the quality of evidence. During Covid, we would do a piece of work, we would run a trial, and we would test something with thousands of people. The results would be clear that they understood one option much better than the other option. And then a different choice would be made on the basis of a focus group where one person in the focus group didn’t like it. Which should you weigh more?

There’s that old saying in advertising that only 50% of it works, but you don’t know which 50% it is. We don’t even know that; we’re not even close to that. Public service is full of people who came in because they wanted to have a positive impact, but they just don’t know – they’re blind – because of a lack of empiricism. We don’t test systematically or look for variance in the system.

I sometimes find it hard to contain my frustration. We’ve got to be better at telling the difference between good and bad evidence. Then, we might go forward. I’ve always said that if you go from being so unempirical, and you then start doing it properly, imagine what’s possible. It’s like the unfinished enlightenment: you’ll literally get to see where you’re going. If we’re spending a trillion a year, we should be waking up at night thinking: “Was that the best thing we could have done with that money?”
Avoiding the forces of inertia
There’s a period between being naïve and being jaded when you’re really useful. If you’re at the point of dragging yourself through the shiny black door of No.10, you should get out of the way and let someone else go in. Public life at a senior level is a huge privilege. I was incredibly lucky to work with Jeremy Heywood. I remember talking to him often, wringing my hands and saying: “We had that discussion with the perm secs but none of them have done it, Jeremy!” And he’d say: “Yes, but we don’t give up!”

Improving the civil service
An interesting question government could ask is: “What are we doing to improve our public servants?” Government is the institution that should improve other institutions. When the Institute for Government was built in Britain, we still had the National School of Government. The latter was shut down without a replacement. We can’t expect our institutions to get better without supporting the people within them.

In 2007, I met a friend who ran the Civil Service College in Singapore. In a country less than a 10th of the UK’s size, their civil service was put through more training than we offer. The head of the college worked part time between that and the PM’s office. How are we helping our civil service sharpen and build their skills? At best, we have unfinished institutional arrangements to support upskilling. 

Read the most recent articles written by Jess Bowie - Lunch with... civil service skills evangelist Pamela Dow


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