Silver tsunami is a metaphor used to describe population aging; specifically, baby boomers reaching the age of 65 starting in 2011. This demographic shift will result in a massive expansion to the number of people living in first world nations over the age of 80. The term silver tsunami metaphor has been employed in both popular media and in scholarly literature to refer to the late-twentieth-century demographic shift towards population aging. This phenomenon has been documented in prominent media outlets, such as The Economist, Forbes.com, and multiple news outlets. It has also been used to refer more specifically to the health and economic implications associated with population aging by major medical publications, including The British Medical Journal, New England Journal of Medicine, and professional organizations including American Psychological Association.