According to Wikipedia,
U.S. economy (GDP) $14.266 trillion (2009)
China economy (GDP) $4.99 trillion (2009) (though it's actually $5.34 trillion today (multiply the quarter numbers above by 4)
Japan economy (GDP) $5.073 trillion (2009) (nominal; 2nd)
And yet...
China close to catching U.S. in manufacturing
By Chris Isidore, senior writerJune 21, 2010: 3:52 PM ET
NEW YORK (CNNMoney.com) -- China's manufacturing sector is on the brink of passing that of the United States, according to a report released Monday.
Analysis of the latest government readings by economic research firm IHS Global Insight show that China's manufacturing sector nearly caught the U.S. output in 2009. The value of goods produced by China's factories reached about $1.6 trillion last year, compared to $1.7 trillion by U.S. manufacturers.
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More here...And that was in only 30 years. Given the billions China is investing in its people they are likely to be the world leaders in solar\alternative technologies and polysilicone production (computers and nearly anything electronic) in less than another 30.
Assuming we sit here and don't invest in our people.
...
And Chinese producers are hardly standing still. In a recent survey of Chinese and U.S. manufacturers by Industry Week, 54% of Chinese companies cited innovation as one of their top objectives, while only 26% of U.S. respondents did. Chinese companies spend more on worker training and enterprise-management software. And 91% of U.S. plants are more than a decade old, vs. 54% in China....
More here...'Course, that's an evaluation by a group trying to sell automation to U.S. manufacturers, but still...