This textbook is an extended material from my various lecture notes from 2005 to the present. I am grateful for a number of friends and colleagues who encouraged me to start the work, persevere with it, and finally to publish it. First, I would like to thank Almighty God for giving me the power, capacity and knowledge to think and decide to write this textbook. Second, I would like to pay special thankfulness, warmth and appreciation to experts who agreed my invitation to hold an expert review session for the purpose of improving and shaping this textbook. They are well knowledgeable and have been teaching microeconomic topics for long time in various universities. These are Dr. Natu Mwamba, Dr. Nicholaus Kessy, Dr. Balozi Morwa, Dr. Mnaku Maganya, Dr. Genuine Martin and Dr. Lusajo Mwankemwa. I would not be able to get my work well done without the financial support from the Bank of Tanzania for financing review sessions of this textbook. I am especially indebted to the late Prof. Amon V.Y. Mbelle who had been supportive of my career goals and who had been mentoring and providing me with the protected academic time to grow professionally. May the Almighty Lord rest his soul in eternal peace. For valuable help in the preparation of the textbook, I would like to thank Dr. Nicholaus Kessy for critical and helpful comments on early draft. Finally, I would like to thank Ms. Celina Kaserah for her assistance in the final stages of the preparation. Last but not least; I wish to thank my employer, the Bank of Tanzania for granting me enough time to prepare the textbook. Nobody has been more important to me in the pursuit of this textbook than the members of my family. I would like to thank my brother Mr. Thomas Buhahate who has been playing a role as my father since departure of my father from this world. He really loves me and provides guidance in whatever I pursue. Most importantly, I wish to thank my loving and supportive wife, Mrs. Sara Nicas, and my two wonderful children, Better and Isaack, who provide endless inspiration. This textbook is dedicated to my late loving son, Kelvin, who was called by God to eternal glory in February 2021 and my remembrance for him will be never ending.