This book is about retirement income security. This income security is provided by national public pensions, corporate pensions, and individual and reverse mortgages. However, these systems vary greatly from country to country and, in many countries, do not provide sufficient coverage. Ensuring income security in old age is an important issue that must be resolved in the rapidly aging environment of the world. From the perspective of financial consumers, this book cross-sectionally surveys public pensions, corporate pensions, individual pensions and reverse mortgages and compares them among many important nations. This gives many implications from the perspective of designing an overall income security for each individual. In addition, it presents many of the issues needed for these sustainable and comprehensive income security.