- 「不換紙幣が交換価値を持つのは、発行した通貨で支払われる経済活動に対して課税できる主権があるからだ」
Chartalism Chartalism - Wikipedia
In macroeconomics, chartalism is a heterodox theory of money that argues that money originated historically with states’ attempts to direct economic activity rather than as a spontaneous solution to the problems with barter or as a means with which to tokenize debt, and that fiat currency has value in exchange because of sovereign power to levy taxes on economic activity payable in the currency they issue.