0The Ninth Decade is a path-breaking and timely book on aging: the first to focus explicitly and at length on eighty-somethings, the fastest-growing demographic in the industrialized world. Covering eight years in lively six-month installments, Klaus tells a vivid story not only of his own ninth decade and survival routines, but also of his loving companion, Jackie, who is strikingly different from him in her physical well-being, practical outlook, sociable temperament, and vigorous workouts. Cameos of their octogenarian friends and relatives near and far add to a wide-ranging and revelatory portrayal of advanced aging, as do bios of notable octogenarians.

The multi-year scope of his chronicle reveals the numerous physical and mental problems that arise during octogenarian life and how eighty-year-olds have dealt with those challenges. The Ninth Decade is a unique, first-hand source of information for anyone in their sixties, seventies, or eighties, as well as for persons devoted to care of the aged. Though the challenges of octogenarian life often require specialized care, The Ninth Decade also shows the pleasures of it to be so special as to have inspired Lillian Hellman's paradoxical description of "longer life" as "the happy problem of our time."