This book is the English version my book Fundamental Theories of Natural Resource and Infrastructure PPP/Project Finance, which was published in Japanese by Kinzai Institute for Financial Affairs, Inc. (Ippan Shadan Houjin Kinyu Zaisei Jijyo Kenkyukai) in 2014. Although the English and Japanese versions of this book generally address the same topics, they do differ in certain respects. The Japanese version deals with certain topics that are particular only to Japan and thus are not mentioned in this book. Furthermore, the English version contains certain topics that reflect relevant developments that are not mentioned in the Japanese version published in 2014. Public–private partnership (PPP) is now a common arrangement implemented throughout the world, but for each person involved in such projects, the definition of PPP is different. In addition, PPP is not the sole arrangement by which private companies provide public services. For certain infrastructure projects involving the provision of public service, deregulated privatization might be preferable over PPP.1 In this book, I have categorized some types of PPP projects to which several well-established business theories for PPP are applied. I believe that only PPP projects that fall within such categories should be considered true PPP projects, but this is a matter of definition. However, the reader should understand at least that if PPP is defined more broadly, the abovementioned well-established business theories for PPP would apply only to specific types of PPP projects and not all PPP projects.