Iam grateful to My family include father, mother , brother and sister for support me on write this book through fund and encouragement. Iam also grateful to my friends and my colleagues, include Ladslaus Urassa, Hemed Hamidu, Stephen Paghah, Steven Ainea and Elisha Munuo for support me by give their advice and Idea. Thanks to Mzumbe University lecturer for create knowledge on me about economic and much support to my work. Special thanks must be for my sister Angela Tarimo for her great hope and also support she give to me on type this book.