WTF China?

[bobman0330]

http://www.marginalrevolution.com/ma...estimate-.html

apparently, China's economy is actually 40% smaller than usually stated, measured according to purchasing-power parity. I don't have any deep knowledge of this area, but this seems pretty shocking to me. Anyone have any insight into what this really means? Is China less of a threat to run amok and conquer the mid-21st century? More?