https://blog.wongcw.com/2021/09/27/%e7%be%8e%e7%b6%93%e6%bf%9f%e5%ad%b8%e5%ae%b6%e7%a8%b1%e5%8d%81%e5%b9%b4%e5%85%a7%e7%8f%be%e9%87%91%e5%b0%87%e6%b6%88%e5%a4%b1/
美經濟學家稱十年內現金將消失