 I want to discuss the economics of high density cities. So kind of business model for high density cities, so to speak. The question is, how can we make these cities livable and affordable to more people? So in Chinese cities, in Chinese characters, you're made of Chen, which is a building and a physical capital. And the city is people and the market. OK, so last year, Chinese invested more than 50% of GDP in urban real estate infrastructure and manufacturing jobs to create cities. And this is a model, a high capital intensive model for fast urbanization. So the question is whether a huge investment can create livable cities. Now, livable cities are not just a place that's nice. Livable cities enable people to meet and trade easily so that they can be creative and productive. It's a place that people can use less resources and manage the resource well. But we often price cities for its capacity to generate GDP. And we can have more GDP by just investing more capital in place, hire more people, mass production, and we can mass-produce cities with capital. But the capital intensive urbanization makes people dependent on cars and other capital for their mobility and for their livelihood. And ironically, higher car ownership does not always make mobility easier in the city. And it does reduce the space for pedestrian and for community life. And the mass production of housing does not always make urban living affordable. If people have to depend on distant jobs and depend on high consumption of energy. So the capital intensive urbanization inevitably reach diminishing returns. And this is a case in China. We can see the investment spree in the last decade has made many Chinese cities highly in-depth. And that shows more capital investment doesn't generate livable cities that can generate enough income. So we need to employ our capital more smartly to make cities do more with less so that urbanization can be sustained. So capital should liberate people, enable them to contribute to communities. So if we use the capital smartly, livable cities don't have to be expensive. Cotiba, a Brazilian city, about 1.7 billion people, is a good example. Its bus rapid transit system is cheap. It's low cost. But it's so good that it reduced the car traffic in the city by 30% while the population traveled in 20 years. And the city also has recycled programs that allow people to be productive. Even children can be productive to help the community to reduce waste and make the community clean. So livable cities are not real city projects. So livable city is about choice of how we live and how we work. It's a choice of technology and institution that enable people to shape their build environment and the collective behavior. Livability also creates high density by attracting people to increase proximity and enable public collective choice that managed resource well. So the good news is the technologies are becoming more scalable and more intelligent. And that enable give more possibilities for people to be productive in different ways and to manage resources more responsibly. But for the benefit of the new technology to be realized, we need innovation. And innovation requires communities, requires collective actions by community that take ownership in their environment and in the deployment of technology. But one question you may ask is whether this decentralized investment decision making by smaller communities would produce inefficient cities? And here we have an example of a relatively small country but with highly decentralized and diverse urban system. So Swiss cities are very efficient and inclusive and environmental friendly. So the question I have for you is, how do we enable innovations that make city do more with less and provide something for everyone? And with these innovations, high density cities can be livable place where everyone gains.