Earlier this year, Andrew Haldane, Chief Economist at the Bank of England, gave a fascinating speech on "Growing, fast and slow." In it he succinctly sums up the history of economic growth. As he notes, "If the history of growth were a 24-hour clock, 99% would have come in the last 20 seconds." Given that economic growth is a very new phenomenon, he goes on to look at where growth comes from. Specifically, he outlines the difference between the Neo-Classical exogenous growth model (where innovation is an outside random factor - "manna from heaven") and the "New Growth Theory" endogenous growth model (where innovation is a function of internal factors).