[A] defining feature of the US financial system is that its central bank, the Federal Reserve, has inordinate influence over global monetary conditions. Because of this influence, it shapes the growth path of global aggregate demand more than any other central bank does. This global reach of the Federal Reserve arises for three reasons.
First, many emerging and some advanced economies either explicitly or implicitly peg their currency to the US dollar given its reserve currency status. Doing so, as first noted by Mundell (1963), implies these countries have delegated their monetary policy to the Federal Reserve as they have moved towards open capital markets over the past few decades.
These “dollar bloc” countries, in other words, have effectively set their monetary policies on autopilot, exposed to the machinations of US monetary policy. Consequently, when the Federal Reserve adjusts its target interest rate or engages in quantitative easing, the periphery economies pegging to the dollar mostly follow suit with similar adjustments to their own monetary conditions.
The second reason for the global reach of US monetary policy is that a large and growing share of global credit is denominated in dollars. That means the Federal Reserve’s influence over the dollar’s value gives it influence over the external debt burdens of many countries.
The third reason for the extended reach of US monetary policy is that other advanced- economy central banks are likely to be mindful of, and respond to, Federal Reserve policy given the large size of the dollar bloc… These findings imply that even inflation- targeting central banks in advanced economies with developed financial markets are not immune from the influence of Federal Reserve policy. This has led Rey (2013, 2015) to argue that the standard macroeconomic trilemma view is incomplete.
Our central finding is that the US dollar scores (by a wide margin) as the world’s dominant anchor currency and, by some metrics, its use is far wider today than 70 years ago.