Acknowledgments

This book could not be finished without the help from so many people. I thank my Ph. D. advisors, Eric Bahel and Hans Haller, at the Department of E-conomics of Virginia Tech. They both read quite carefully all my manuscripts from the very beginning of this work, and I am truly indebted to them for their invaluable comments, suggestions, encouragements, and supports. I also benefited a lot from the talks with Professor Haller. She is an outstanding example teaching me that a researcher should commit herself to delving deep into the topics she is interested in, rather than wasting time on pursuing all kinds of introductory-level knowledge. I am also grateful to my committee members, Joao Macieira and Zhou Yang, for their kind and helpful comments and suggestions on my research. I want to thank Richard Ashley, Amy Stanford, Sara Tickle, and Sherry Williams for their excellent support that really made my Ph. D. study convenient and comfortable. It had been a wonderful experience for me to have Lei Pan as my roommate for the 6 years of my Ph. D. study, during which most parts of this book had been initiated and concretized.

I further thank Changsheng Xu, Jiaqiang Zhuang, Shihui Ma, Kui Zhao, Tiefeng Qian, and so many teachers and colleagues at Huazhong University of Science and Technology, the discussions with them helped me a lot in completing this book.

Special thanks are also extended to my teachers, friends, and relatives in both China and the United States. This book has also been supported by the Fun-damental Research Funds for the Central Universities, HUST: 2016AB007.

Finally, I am deeply indebted to my parents, Xianliang Yi and Shubin Wang, my wife, Lei Chen, and our son, Chuheng Yi. They have always been supporting and understanding me. This book is dedicated to them.