---- Acknowledgments ----
We would to like thank Shi He, Roger Lee, and Tianyu Wang for research assistance. Useful comments of Michael Hutchison, Paul Luk, Kishen Rajan, Frank Westermann, Matthew Yiu, and the participants at the Conference on Global Safe Assets, International Reserves, and Capital Flow, May 20-21, 2019, Hong Kong are gratefully acknowledged. Of course, we are responsible for any remaining deficiencies or errors. The work described in this paper was partially supported by a grant from the Research Grants Council of the Hong Kong Special Administrative Region, China (Project #: CityU 11500617). Aizenman gratefully acknowledges the financial support of the Dockson Chair at the University of Southern California. Cheung gratefully acknowledges the Hung Hing Ying and Leung Hau Ling Charitable Foundation (孔慶熒及梁巧玲慈善基金) for its support through the Hung Hing Ying Chair Professorship of International Economics (孔慶熒講座教授(國際經濟)). The views expressed herein are those of the authors and do not necessarily reflect the views of the National Bureau of Economic Research.