Agequake: Riding the Demographic Rollercoaster Shaking Business, Finance and our World is a book written by Paul Wallace and published in 1999, that investigates what possible ramifications are likely as a significant and unprecedented portion of the human population age. The book argues that rising longevity and lower fertility is causing a seismic shift in the profile of populations worldwide, and will be a fundamental force to that will shake business and finance, along with lifestyles and attitudes. Wallace suggests the old bogey of overpopulation is being replaced by a population "implosion".