$123,000,000,000,000 - China’s estimated economy by the year 2040.

In 2040, the Chinese economy will reach $123 trillion, or nearly three times the economic output of the entire globe in 2000. China's per capita income will hit $85,000, more than double the forecast for the European Union, and also much higher than that of India and Japan. In other words, the average Chinese megacity dweller will be living twice as well as the average Frenchman when China goes from a poor country in 2000 to a superrich country in 2040. Although it will not have overtaken the United States in per capita wealth, according to my forecasts, China's share of global GDP -- 40 percent -- will dwarf that of the United States (14 percent) and the European Union (5 percent) 30 years from now. This is what economic hegemony will look like. 

Most accounts of China's economic ascent offer little but vague or threatening generalities, and they usually grossly underestimate the extent of the rise -- and how fast it's coming. (For instance, a recent study by the Carnegie Endowment for International Peace predicts that by 2050, China'seconomy will be just 20 percent larger than that of the United States.) Such accounts fail to fully credit the forces at work behind China's recent successor understand how those trends will shape the future. Even China's own economic data in some ways actually underestimate economic outputs.

It's the same story with the relative decline of a Europe plagued by falling fertility as its era of global economic clout finally ends. Here, too, the trajectory will be more sudden and stark than most reporting suggests. Europe's low birthrate and its muted consumerism mean its contribution to global GDP will tumble to a quarter of its current share within 30 years. At that point, the economy of the 15 earliest EU countries combined will be an eighth the size of China's.

This is what the future will look like in a generation. It's coming sooner than we think. What, precisely, does China have going so right for it?

The first essential factor that is often overlooked: the enormous investment China is making in education. More educated workers are much more productive workers. (As I have reported elsewhere, U.S. data indicate that college-educated workers are three times as productive, and a high school graduate is 1.8 times as productive, as a worker with less than a ninth-grade education.) In China, high school and college enrollments are rising steeply due to significant state investment. In 1998, then-President Jiang Zemin called for a massive increase in enrollment in higher education. At the time, just 3.4 million students were enrolled in China's colleges and universities. The response was swift: Over the next four years, enrollment in higher education increased 165 percent, and the number of Chinese studying abroad rose 152 percent. Between 2000 and 2004, university enrollment continued to rise steeply, by about 50 percent. I forecast that China will be able to increase its high school enrollment rate to the neighborhood of 100 percent and the college rate to about 50 percent over the next generation, which would by itself add more than 6 percentage points to the country's annual economic growth rate. These targets for higher education are not out of reach. It should be remembered that several Western European countries saw college enrollment rates climb from about 25 to 50 percent in just the last two decades of the 20th century.

And it's not just individual workers whose productivity jumps significantly as a result of more education; it's true of firms as well, according to work by economist Edwin Mansfield. In a remarkable 1971 study ,Mansfield found that the presidents of companies that have been early adopters of complex new technologies were on average younger and better educated than heads of firms that were slower to innovate.

The second thing many underestimate when making projections for China's economy is the continued role of the rural sector. When we imagine the future, we tend to picture Shanghai high-rises and Guangdong factories, but changes afoot in the Chinese countryside have made it an underappreciated economic engine. In analyzing economic growth, it is useful to divide an economy into three sectors: agriculture, services, and industry. Over the quarter-century between 1978 and 2003, the growth of labor productivity in China has been high in each of these sectors, averaging about 6 percent annually. The level of output per worker has been much higher in industry and services, and those sectors have received the most analysis and attention. (I estimate that China's rapid urbanization, which shifts workers to industry and services, added 3 percentage points to the annual national growth rate.) However, productivity is increasing even for those who remain in rural areas. In 2009, about 55 percent of China's population, or 700 million people, still lived in the countryside. That large rural sector is responsible for about a third of Chinese economic growth today, and it will not disappear in the next 30 years.

Third, though it's a common refrain that Chinese data are flawed or deliberately inflated in key ways, Chinese statisticians may well be underestimating economic progress. This is especially true in the service sector because small firms often don't report their numbers to the government and officials often fail to adequately account for improvements in the quality of output. In the United States as well as China, official estimates of GDP badly underestimate national growth if they do not take into account improvements in services such as education and health care. (Most great advances in these areas aren't fully counted in GDP because the values of these sectors are measured by inputs instead of by output. An hour of a doctor's time is considered no more valuable today than an hour of a doctor's time was before the age of antibiotics and modern surgery.) Other countries have a similar national accounting problem, but the rapid growth of China's service sector makes the underestimation more pronounced.

Fourth, and most surprising to some, the Chinese political system is likely not what you think. Although outside observers often assume that Beijing is always at the helm, most economic reforms, including the most successful ones, have been locally driven and overseen. And though China most certainly is not an open democracy, there's more criticism and debate in upper echelons of policy making than many realize. Unchecked mandates can of course lead to disaster, but there's a reason Beijing has avoided any repeats of the Great Leap Forward in recent years.