In 1930, the world’s first ‘celebrity economist’ Irving Fisher wrote a book titled ‘The Theory of Interest: As Determined by Impatience to Spend Income and Opportunity to Invest It’. The upshot of this was an equation that split the profession of economics and policymaking down the middle.
Fisher’s idea was simple: anywhere that currency was used, the amount of money in the system and the frequency with which it changed hands, was the best indicator of prices and the health of the economy.

