To understand the US consumer you must understand US demographics. Two generations dominate US population the Baby Boomers and the 'Millennials'. How these generations choose to live and spend will ultimately determine the pace of US consumption growth and thus GDP growth to 2035. Using survey data and demographic forecasts this Insight explains why US consumption growth peaked in 1999 and perhaps more importantly explains why consumption growth is now close to half that rate. Given the demographic profile of the US consumption growth is expected to remain subdued held back by the reduced spend of the Baby Boomers as they retire. Given the change in spending behaviour of the Millennial generation largely down to increased indebtedness Millennials will fail to offset this decline. The US is headed for a sustained period of weak consumption growth.