Just before the bankruptcy of the Mt. Gox bitcoin digital-money (or virtual-currency) exchange, Japanese finance minister Taro Aso predicted the inevitable failure. “No one recognizes them as a real currency,” he told reporters. “I expected such a thing to collapse.”

I totally agree with Mr. Aso. For weeks and weeks I have been tweeting and broadcasting that bitcoin is not real money. It is not a reliable medium of exchange, nor is it a reliable store of value. It has no central-bank regulation, network operations or even centralized issuance. And because of its wild price fluctuations, bitcoin can never be a reliable payment system.