BITCOIN, Ethereum, XRP, Stellar, Cardano: the infant world of cryptocurrencies is already mind-bogglingly crowded. Amid the cacophony of blockchain-based would-be substitutes for official currencies, central banks from Singapore to Sweden have been pondering whether they should issue digital versions of their own money, too. None is about to do so, but a report prepared by central-bank officials from around the world, published by the Bank for International Settlements on March 12th—a week before finance ministers and central-bank heads from G20 countries meet in Buenos Aires—offers a guide to how to approach the task.

比特币、以太坊、瑞波币、恒星币和艾达币：这些加密货币界初出茅庐的货币多得令人难以置信。在基于区块链的货币将要取代官方货币的吵杂声中，从新加坡到瑞典的各国中央银行也一直在考虑是否要发行本国货币的数字版本，但没有任何一个国家真的打算这样做。不过，各国央行官员编写的一份报告为如何实现这一目标提供了指导。该报告由国际清算银行于3月12日发布，时间正好是20国集团国家的财长和央行行长在布宜诺斯艾利斯出席会议的前一周。

The answer? With care. For a start, it matters who will be using these central-bank digital currencies (CBDCs). Existing central-bank money comes in two flavours: notes and coins available to anyone; and reserve and settlement accounts open only to commercial banks, already in electronic form (though not based on blockchain) and used for interbank payments. Similarly, CBDCs could be either widely available or tightly restricted. A CBDC open to all would in effect allow anyone to have an account at the central bank.

答案是什么呢？要小心。首先，谁将使用这些央行数字货币 (CBDCs)，这个很重要。现有的央行货币有两个特点：一是可供所有人使用的纸币和硬币；二是只对商业银行开放的准备金账户和结算账户（虽然以电子形式存在，但还不是基于区块链的）用于银行间的支付。类似地，央行数字货币可以开放，也可以限制。一种对所有人都开放的央行数字货币实际上将会允许任何人都拥有央行账户。

CBDCs could be transferred either “peer to peer”, like cash, or through the banking system. They could be held anonymously, preserving the privacy of cash, or tagged, making it easier to trace suspicious transactions. Should they bear interest, that would affect demand not only for CBDCs but also for cash, bank deposits and government bonds.

央行数字货币可以“P2P”方式转移，如现金或银行系统。这些数字货币能以匿名持有，保持现金的私密性，或被标记，使之更容易追踪可疑交易。如果他们有兴趣，这不仅会影响央行数字货币的需求量，还会对现金、银行存款和政府债券产生影响。

The report weighs up CBDCs’ possible effects on payment systems, monetary policy and financial stability. A steep decline in the use of cash could strengthen the case for a widely available CBDC. In Sweden the Riksbank is contemplating an “e-krona” for small payments. But in most countries, despite the growing use of cards, accelerated by the advent of contactless payments, cash remains popular (see chart). Experiments with a CBDC just for interbank payments, says the report, have “not shown significant benefits”.

上述报告衡量了央行数字货币对支付系统、货币政策和金融稳定性可能存在影响。现金使用的急剧减少情况可能会强化开放央行数字货币的情形。瑞典央行正在打算发行“e-克朗”用于小额支付。不过，在大多数国家，尽管非接触式支付的出现使信用卡的使用越来越多，现金依旧很受欢迎（见图表）。上述报告称，央行数字货币的尝试仅用于银行间支付，尚未显现出实际好处。

A widely available, interest-bearing CBDC could, in principle, tighten the link between monetary policy and the economy. An interest rate tied to the policy rate may put a floor under money-market rates. Banks may have little choice but to pass changes in the CBDC rate on to depositors. Negative rates would be easier to implement, especially if high-denomination banknotes were abolished. But all this is uncertain. Retail depositors are less sensitive than institutional investors to changes in rates. Central banks already have plenty of tools. The authors are not sure that the putative gains yet warrant creating CBDCs.

从原则上来说，一个广泛实行并有利息的央行数字货币可以巩固货币政策和经济之间的联系。与政策利率挂钩的利率可能会给货币市场利率设置下限。各家银行可能别无选择，只能把央行数字货币的利率变动转嫁给储户。尤其是在废除大面额钞票之后，实施负利率将变得更加容易。但一切都是不确定的，零售储户对利率变动的敏感程度不如机构投资者。央行拥有了大量政策工具。前述报告的作者还不确定这种假定收益能否保证央行数字货币的创造。

On financial stability, they are more cautious still. In times of stress, depositors flee wobbly banks for safer homes—and a CBDC would allow “digital runs” to the central bank. Even in normal conditions, banks would face higher funding costs if they had to compete with the central bank for deposits. Digital versions of currencies used internationally (eg, the dollar) could worsen these complications, if foreigners were free to use them.

他们对待金融稳定更为谨慎。面临压力时，储户从不稳定的银行逃往更安全的去处，央行数字货币则允许“数字流”流向央行。即使是在正常情况下，银行如果要与央行争夺储户，他们也会面临更高的融资成本。如果外国人可以自由使用数字货币（如美元），那么其在国际范围内的使用可能会恶化这些影响。

Central bankers focus more on the rise of private crypto-currencies, warning that they are speculative gambles. Expect more such admonitions in Buenos Aires—and no rush to mint CBDCs.

央行更多关注于私人加密货币的增长，警告它们是投机赌博。预计在布宜诺斯艾利斯会有更多类似警告——不会急于发行央行数字货币。

编译：卢语欣

编辑：翻吧君

来源：经济学人（2018.03.10）