Ackowledgements
We thank the HKU Foundation and University
of Macau for financial support. We thank Bai
Chong-en, Joseph Fan, Zhang Junxi, Kim
Woochan, Keith Lam, Lewis Tam and William
Cheung, and two anonymous reviewers for their
constructive comments on this article. We also thank
Ms. Cheung Pui Ki for her excellent research
assistance.