 Over the last 30 years. Over the last 30 years. Over the last 30 years. Lots of people feel uncomfortable about aid giving, but at the end of the day when you actually think of aid as a resource and when it's used properly, it does pay off like good investments. The overall international aid effort seen as an investment has given a rate of return of 10% per year. So when we started 30 years ago to research these issues, the data were very, very contradictory. It's very hard to get statistically significant evidence when the database is weak. Now that has been building up and that's why we are today now much more certain about being able to find, identify the relationship between aid and overall development. Before 2008, there were more studies saying, well, we can't find the evidence. It doesn't seem to be there. Thus it was concluded that the impact of aid wasn't there. See all of the poor countries that are growing and those who are growing often have aid as an important factor. Take Vietnam, which I have now worked with for 15 years. Vietnam was for years the largest recipient of aid in the world. Everybody says that Vietnam has done very well and I can certainly confirm that. What we're doing now, they're pulling out of Vietnam. So does that mean that aid didn't work? No, it's a signal of success that we no longer have to give aid. If you're trying to change conditions in a country where you have a corrupt government and there are definitely examples of not getting it right. But the important question is, does it pay off overall? And that's what we have shown that it does. It's important to understand that at the end of the day aid is a relatively small share of the overall resource flow. So getting aid right is important. But the big challenge is to get these many other actions that national governments take right. When aid flows are high to a particular country it's only about $25 per person per year. Think about what you can get for $25. That's not per se going to be a complete game changer. You can have a rate of return on the aid of 10%. That doesn't mean that the whole economy is growing by the same rate. It can help transfer or share knowledge. Knowledge is a critical element of development. If you invest in better health services people are going to be surviving and they are going to be more productive. They're going to produce more than they otherwise would. If you are healthy you're stronger and you produce more. So if you make that investment in health services and these people produce more you're going to get a rate of return. That's what we mean. Over the next 30 years in my assessment it's going to continue to play an important role but aid is only one element. The more aid can be catalytic the more it can help promote for example private investment. That's a good thing. Some of the challenges are going to be to make sure that the resources available are used even more effectively because that is indeed possible. It's also going to be to try to use aid in a way that will help governments address those many new challenges that are going to come. For example, the area of climate change. It's going to be very critical that the knowledge that exists in the world is made available to these countries in development. Aid can help promote that exchange of knowledge.