Economists who studied in the '80s tend to have a pretty crude neoclassical view that's just about freeing up prices and markets, and then you'll get the growth and everybody benefits. And they'll just repeat that, because if you're a minister or a senior civil servant, you don't have time to read anything anymore. You get very fixed in your views.

In the end, that's a blind alley - we have to get back to being able to think on our feet and react.

Activists can get very preachy about things. It's more about understanding people's own experiences and tapping into them.

Until you have looked in depth at the system and found out where women in Egypt are not being cut through female genital mutilation, or where kids in Vietnam are not malnourished, or where hospitals in America are getting rid of the superbugs anyway - unless you have that level of curiosity about what's going on without you, you will always come in with your great new recipe and just ignore what's going on, and that will make you much less effective at what you're trying to achieve.

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.

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

When we do work in places like China and Vietnam, research tends to be really effective as a way of getting change, whereas in more open places, mobilization and the creation of public pressure through the media often seem to be the things we try.