Received 9 August 2009Accepted 9 October 2009Responsibility for all errors, omissions, and opinions rests solely with the author. The findings, interpretations, and conclusions expressed herein are those of the author and do not necessarily reflect the views of the World Bank and its affiliated organizations, or those of the Executive Directors of the World Bank or the governments they represent.
The author would like to thank Philippe Dongier, Tim Kelly, Yongsoo Kim, Siou Chew Kuek, Siddhartha Raja, Rajendra Singh, Eloy Vidal and Mark Williams for their comments and suggestions, and Siou Chew Kuek for preparing the draft Appendix.