We should look at how "the enemy" - people that you wouldn't necessarily agree with - have done change and see whether there's bits in there that we could learn from.

You have a huge number of people who spend their time writing papers which show that migrants pay more to the country than they take out in benefits, and they say, "Why don't you approve of migration? Why don't you open up borders?" They're not able to empathize with how people feel about migration.

What you don't do is just say, "I've got all the ideas and all the knowledge, and listen to me."

People think there's a single solution to complex problems, and the solution is often making an enemy of a group of people - pulling back and rejecting the other.

Lots of people in the open system are very determined to try and strengthen evidence-based policy.

There are always pressures on decision-makers other than just what is right or what is wrong.

There's a tendency for people who believe passionately in something to be so convinced of their rightness that if they just repeat themselves a lot at the person, that will convince them. And that hasn't worked on things like immigration or trade deals.