In the words of the American economist Abba Lerner, from his essay in the 1947 edition of the American Economic Review

“The modern state can make anything it chooses generally acceptable as money . . .It is true that a simple declaration that such and such is money will not do, even if backed by the most convincing constitutional evidence of the state’s absolute sovereignty. But if the state is willing to accept the proposed money in payment of taxes and other obligations to itself the trick is done.”