 Well, we've talked about population aging and population decline in the developed world. But in fact, much of the developing world will be aging very rapidly as well, including China. I sometimes call this the second wave of global aging. China is a much younger country than the United States is today, and will remain younger for the next couple of decades. By 2035 or 2040, it will actually have an older age structure than the United States does. Fertility has fallen dramatically in China, and as indeed it has throughout East Asia. The Chinese fertility rate is now about 1.7 or 1.8, in part the result of the one-child policy. China's workforce, which has been rapidly expanding and adding about two or three percentage points a year to GDP growth, will peak in 2015 and then begin to decline. It's been adding two to three percent a year, it will be subtracting one to two percent a year, which will put a break on growth in the future. But the most important thing to keep in mind, I think, is that the basic fiscal and economic challenge of an aging population in China and also in other parts of the developing world is fundamentally different than it is in the United States and the developed world. In the rich world, the challenge is how to afford the cost of over-generous promises that were made in a different demographic universe, back when there were a lot of young workers and relatively few retirees. That's a big challenge, but we're affluent societies, and if we proceed with some foresight and forethought adjustments can be made, the challenge in China is very different. In a very real sense, despite the rapid economic growth of the past two decades, China's still on the threshold of becoming a middle-income country. It's not a high-income country. And it won't be a high-income country in any plausible growth scenario by the time the age wave hits in 2025. So it's a race to get rich before it gets old. There will be 400 million Chinese elders aged 60 and over by the year 2040, 100 million aged 80 and over, most of whom will not have pensions and will not have health care. They're depending on their extended family, on their grown children, but the government told them not to have children or not to have as many. There's a huge humanitarian crisis looming in China's future, which has a very important economic and also political implications.