It is surprisingly difficult to find economic variables that strongly co-move with exchange rates, a phenomenon codified in a large literature on “exchange rate disconnect.” We demonstrate that a variety of common proxies for global risk appetite, which did not co-move with exchange rates prior to 2007, have provided significant in-sample explanatory power for currencies since then. Furthermore, during 2007-2012, U.S. purchases of foreign bonds were highly correlated with these risk measures and with exchange rates. Our results support the narrative that the US dollar's role as an international and safe-haven currency has surged since the global financial crisis.

中文翻译：

---

汇率重新连接

很难找到与汇率密切相关的经济变量，这一现象编入了大量关于“汇率脱节”的文献中。我们证明，自 2007 年以来，全球风险偏好的各种常见指标（在 2007 年之前与汇率不相关）为货币提供了重要的样本内解释力。此外，在 2007-2012 年期间，美国购买外国债券与这些风险指标和汇率高度相关。我们的结果支持了自全球金融危机以来美元作为国际和避险货币的角色已经飙升的说法。