Changes

In fact, the use of paper currency in China hurt the metals industry in general as mining withered during the Southern Song. <ref> Smith, Paul J. “Do We Know as Much as We Need to Know About the Song Economy? Observations on the Economic Crisis of the Twelfth and Thirteenth Centuries” <i>Journal of Song-Yuan Studies</i> 24 (1994) p. 329</ref> The Song discovery of paper currency truly had a great impact on East Asia, but it would be centuries before Europeans discovered the benefits and drawbacks of using paper notes.

<youtube>https://www.youtube.com/watch?v=mjBgegH40rc</youtube>