11. The quantity theory of money holds that changes in price level are directly related to changes in the money supply. 12. Currently, the quantity theory of money is widely accepted as an accurate model of inflation in the long run. 13. Friedman developed his own quantity theory of money that referred to Irving Fisher's but inherited much from Keynes. 14. Fisher espoused a more succinct explanation of the quantity theory of money , resting it almost exclusively on long run prices. 15. The quantity theory of money was a central part of the classical theory of the economy that prevailed in the early twentieth century. 16. He also, in 1517, set down a quantity theory of money , a principal concept in economics to the present day. 17. John Maynard Keynes criticized the quantity theory of money in " The General Theory of Employment, Interest and Money ". 18. In the quantity theory of money , this is expressed as MV = PY, where money supply times velocity equals price times output. 19. He was an acute critic of nearly all other writers on money, and especially of Irving Fisher and his mechanical quantity theory of money . 20. The quantity theory of money , simply stated, says that any change in the amount of money in a system will change the price level.
