The volatility of crypto currencies hinders their ability to be media of exchange or stores of value, leading to the implementation of exchange-rate pegs in an attempt to stabilize these currencies. This strategy has been used by crypto currencies such as US Dollar Tether, Steem Backed Dollar and TrueUSD; and was previously adopted in countries such as Brazil, Mexico and Argentina. However, an exchange-rate peg is vulnerable to speculative attacks if it is not 100% backed by reserves, as discussed in Obstfeld (1996). Using insights from the bank-run literature, Routledge and Zetlin-Jones (2018) build on Green and Lin (2003) and propose a model of speculative attacks. They show that adjustments to the exchange rate can prevent speculative attacks in equilibrium. They also show how to implement such contracts using blockchain technology. In this discussion paper, I provide a cautionary tale. I show also in a version of Green and Lin (2003) that the information content in the blockchain prevents agents from attaining all the gains from risk sharing—highlighting the downsides of too much public information.

加密货币的波动性阻碍了它们成为交换媒体或价值存储的能力，从而导致实施汇率钉住以试图稳定这些货币。这种策略已被加密货币（例如，美元束线，Steem支持的美元和TrueUSD）使用；先前已在巴西，墨西哥和阿根廷等国家/地区采用。但是，汇率钉住汇率制如果不是100％由储备支持，就容易受到投机性攻击的影响，正如Obstfeld（1996）所讨论的那样。Routledge和Zetlin-Jones（2018）利用银行经营文献的见解，在Green和Lin（2003）的基础上，提出了投机性攻击的模型。他们表明，汇率调整可以防止投机活动达到均衡。他们还展示了如何使用区块链技术实施此类合同。在这篇讨论文件中，我提供了一个警告性的故事。我还在Green and Lin（2003）的版本中证明，区块链中的信息内容阻止代理商从风险共享中获得所有收益-突出了太多公共信息的弊端。