This paper was prepared for the UNU-WIDER Conference on Southern Engines of
Global Growth: China, India, Brazil and South Africa (CIBS), held on 7-8 September
2007 at WIDER-UNU in Helsinki. The author thanks the organizer of this conference
for the invitation to participate in this conference. Fu Yong provided research assistance
and data processing. Comments and suggestions from the participants of this conference
in the revision of this paper are acknowledged