According to official US economic data, the US Gross Domestic Product (GDP) has expanded for 22 quarters, raising real GDP 12.1% above its high prior to the 2008-09 economic contraction. Yet, US manufacturing output and US industrial production have not recovered to their pre-contraction high.  So what is driving the real GDP growth?  In my opinion, the rise in real GDP is an illusion produced by the under-measurement of inflation.