 Technology has surely been one of the main drivers of human development throughout history. Every time that we have mastered the productive opportunities that a new technology brings, we have changed the course of history. Now, given the importance, the potential importance of technology for human development, we should pay a great deal of attention in understanding the general patterns that technology diffusion has followed over time in the past and in the future, as well as the precise mechanisms by which technology affects human development. Until very recently, unfortunately, we knew very little about these big questions. The little that we knew was based on a few studies, focused on a few technologies in a few countries. And therefore, it was very hard to discern whether the conclusions that we draw from these studies represented general patterns or just mere anecdotes. This big gap in our knowledge motivated me about 10 years ago to go and spend time measuring directly the diffusion of dozens of technologies in 150 countries over the last 200 years. And that was quite painful. But after all the pain that gave me the tools to address two questions which I think are critical and which now I can illustrate to you, which are first, what have been the critical patterns in technology diffusion that we have seen over the last 200 years? And second, how critical, how important are those patterns for the dynamics of income that we have observed in the world for the same period? Now, before providing the answers, it's important to distinguish two notions of technology diffusion. The first is the time it takes for technology to arrive to a country. That's the adoption lag. But the second is how intensively we use technology once it has penetrated. Now, we're looking at the data, it's clear that adoption lags have declined dramatically over the last 200 years everywhere. However, the drop in adoption lags has been much larger in poor countries than in rich countries. That's interesting and it's also consistent with the notion that most people have that now technologies are present everywhere. But at the same time it presents a puzzle because it doesn't ring very well with the fact that income per capita has diverged big time over the last 200 years. So how can we reconcile these two facts? How can we solve this puzzle? Well, the solution to the puzzle has to do with the intensity of use of technologies. So for a technology to affect significantly productivity in a country, it needs to both have arrived to the country but also be used intensively. From that perspective, the critical question is, has the gap between the intensity with which new technologies are used in rich countries and poor countries increased or decreased over the last 200 years? Going back to the data, the answer is clear. The gap has increased big time. That is, when you look at how intensively new technologies are used today in rich countries relative to poor countries, this ratio of intensities is way larger than what it watched 200 years ago. So those are the two key facts that characterize the diffusion of technology, convergence in adoption loss and divergence in the intensity of use of technologies. But you may wonder how important is that to explain the dynamics of income across countries? Well, the short answer is very important. Just to give you a sense. You think about the great divergence, the increase in the income difference between rich and poor countries. The trends in technology diffusion, they explain, they are responsible for about 80% of the great divergence we have seen over the last two centuries. And that's basically driven by the divergence in the intensity of use between rich and poor countries. Given the importance of the intensity of use, the question I ask you, the question I pose, is how can we fix this gap with which rich and poor countries have used new technologies? That's the question for our discussion. Thank you.