Fortunately, PhD life has been rewarding. Through my PhD studies, I have many precious memories and, most importantly, many colleagues, friends and family members who supported me and encouraged me to complete it.First of all, I would like to express my deepest and sincerest gratitude to my supervisors, Rob Alessie and Viola Angelini. Looking back on the past four years, I have received countless help and support from you. Thank you for your insightful suggestions and for contributing your experience and knowledge to my research. I am deeply grateful to Rob for his full support and encouragement, especially for providing me with this opportunity to be a PhD student and taking the time to help me become a better researcher. Viola, thank you for your guidance both technically and mentally, and your warm concern during my difficult times. In addition, I would like to thank Viola for always encouraging me to step out of my comfort zone, which has benefited me tremendously. I do not think I can express in words how grateful I am to you all. I could not have achieved this PhD without your supervision and inspiration throughout my PhD journey. I would like to express my gratitude to the assessment committee members: professor Agar Brugiavini, professor Janneke Plantenga, and professor Adriaan Soetevent. Thank you for taking the time to read my thesis and providing valuable comments. In addition, I would like to extend my thanks to those who have helped me with my research. I am grateful to Max Groneck, Bart van Leeuwen, and Sándor Sóvágó for discussing my papers at the SOM PhD conferences, and Raun van Ooijen and Agnieszka Postepska for giving me advices and suggestions during seminars. I would also like to thank my supervisor at the University of Chinese Academy of Sciences (UCAS), professor Jichang Dong. Thank you for your guidance and encouragement during my master and PhD studies, and for your continuous help in many ways. My gratitude goes to many friends and colleagues. I am grateful to my paranymphs and my good friends, Wentao Li and Lina Xie. Thank you for your help and mental support in everyday life and for making my time in Groningen so enjoyable. I want to give a mention to my office mates Nannette Stoffers and Lennart Stangenberg. Nannette, thank you for the lovely painting you did to celebrate Chinese New Year 2019. Lennart, I really enjoy chatting with you about research and life and thank you for making our office a better place to be. I would also like to thank Jasmira Wiersma, Jeroen van der Vaart, Gianmaria Niccodemi, and Laura Viluma, among others. And thanks also to my dear friends back home, Qianlin Zhang, Jingyi Zhao, and Xiaoyu Yuan. Many thanks to all my colleagues in the EEF department and SOM. I would like to thank Taco van der Vaart and Rina Koning for organizing my interviews for the PhD program, HarryGarretson for his helpful advices on the job market, and Ellen Nienhuis, Kristian Peters, Hanneke Tamling, and Arthur de Boer for their continuous support on many administrative issues. I would...