Acknowledgment

I would first like to extend my sincerest thanks to my supervisor, Prof. Dr. Ostap Okhrin, for his guidance, knowledge and patience throughout this work. I appreciate also my advisor, Prof. Dr. Brenda Lopez Cabrera, for her encouragement and comments. I would like to express my gratitude to Prof. Dr. Martin Odening in the Department of Agri-cultural Economics for his support and also to the colleges there, especially to Zhiwei Shen and Stefan Kersting, who enabled me to develop my work. I also appreciate Veronika Blessin for her encouragement in all the time. Deep gratitude is extended to my best friends, Zografia Anastasiadou and Roberto Villanueva Aguirre, for being with me all the time. Their support and encouragement have been of great value for me. A special thanks is also expressed to Roman Brückner for his guidance on pro-gramming so that I could finish this work with the best possible results. Finally, special recognition is expressed to my dear parents, Xueqin and Zhikui, and also my brother, Yongfeng, for their unconditional love, support and encouragement. No matter what kind of decision I made, they have always been standing by me