The authors are grateful for the insightful comments from the senior editor, associate editor, and two reviewers that greatly improved the paper. The authors thank Kenneth C. Wilbur, Kanishka Misra, Karsten Hansen, Kuan-Ming Chen, Chien-Yu Lai, Ming-Jen Lin, and seminar participants at UCSD, Bocconi University, and NTU for valuable comments. The authors also thank Chi-Hsiang Chen and Chung-Kang Lo for their excellent research assistance.