56 – Ethan Ilzetzki on the U.S. Dollar as an Anchor Currency

Episode Summary

Executive Summary: Ethan Ilzetski discusses a new study on exchange rate regimes and anchor currencies, showing the U.S. dollar remains the dominant global anchor and that exchange rates are less flexible than commonly believed. The conversation links these findings to the impossible trinity, the Triffin dilemma, and major implications for U.S. monetary policy and global spillovers.

Main Topics: Career path into economics (Priority: 2/5): Ilzetski explains his shift from electrical engineering and international relations into economics, citing the field’s rigor and his early IMF research experience with Carmen Reinhart and Ken Rogoff. Exchange rate regimes and the impossible trinity (Priority: 5/5): The discussion frames the paper around Mundell’s trilemma: countries cannot simultaneously maintain monetary autonomy, fixed exchange rates, and free capital mobility on a sustainable basis. Methodology for classifying anchors and regimes (Priority: 4/5): The paper uses a statistical algorithm based on exchange-rate behavior to infer both a country’s anchor currency and the tightness of its peg, improving on official IMF classifications. Dollar dominance in the international monetary system (Priority: 5/5): The dollar is shown to be by far the main anchor currency, exceeding all alternatives by a wide margin and reaching what the authors describe as a peak of dollar influence. Historical decline of the pound and rise of the dollar (Priority: 4/5): The conversation traces the pound’s loss of reserve-currency status from the interwar period through Bretton Woods and the postwar transition to dollar dominance. Triffin dilemma and future risks for the reserve system (Priority: 5/5): The reserve currency issuer supplies a global safe asset but also accumulates liabilities; if demand for dollar assets keeps rising, questions arise about sustainability and possible regime shifts. Fiscal multipliers and exchange-rate regimes (Priority: 3/5): Ilzetski briefly summarizes another paper showing fiscal multipliers are larger under fixed exchange rates, in closed economies, and in high-income countries.

Key Arguments: The impossible trinity remains the core constraint: countries can only sustain two of the three goals—fixed exchange rates, independent monetary policy, and free capital mobility. Countries often want exchange-rate stability because private trade, debt issuance, and balance-sheet liabilities are frequently denominated in a dominant anchor currency, especially the dollar. The paper’s classification focuses on actual exchange-rate behavior rather than only official declarations, capturing de facto anchoring and the degree of rigidity. The dollar’s dominance is far greater than that of the euro, yen, or pound; the euro is best understood mainly as a regional anchor. The world is less flexible than commonly assumed: exchange-rate arrangements appear closer to Bretton Woods-style rigidity than the standard narrative suggests. The Triffin dilemma persists in modern form: the reserve currency issuer must supply safe assets to the world, but doing so expands its own liabilities and may create a tipping-point risk. If the Fed tightens policy, the effect transmits globally through dollar-linked exchange rates and capital flows, limiting other countries’ monetary autonomy. Fiscal policy becomes more potent when monetary policy is constrained, such as under fixed exchange rates or near the zero lower bound. The euro faces structural limits as a global anchor because Europe’s share of world GDP is declining and there is no single centrally issued euro-area safe debt instrument. China/renminbi is a possible future challenger, but capital controls and its own dollar peg make it difficult to distinguish from dollar shadowing at present.

Data Points: Share of world GDP anchored to the dollar: ~70% - Highlighted from the paper as the share of global output tied in some form to the U.S. dollar U.S. share of world GDP: 18% - Used to contrast America’s economic size with the dollar’s global reach Share of world GDP anchored to the euro: 12% - Reported as a distant second to the dollar Share of world GDP anchored to the yen: 5% - Reported as a minor global anchor relative to the dollar Share of world GDP anchored to the pound: 2.7% - Reported as a small residual anchor currency share Countries anchored to the pound in the postwar period: about 20% - Mostly former colonies and Commonwealth-linked economies after World War II Time frame of the paper’s data: around 2015 - The dataset and classification end near 2015

Pivotal Quotes: "the U.S. dollar remains by far the most predominant anchor or reference currency" — Ethan Ilzetski: Summarizing the paper’s first headline finding "at best that perception is greatly overstated" — Ethan Ilzetski: Describing the common belief that exchange rates have become much more flexible since Bretton Woods "we’re currently at the height of the dollar’s influence internationally" — Ethan Ilzetski: Explaining the paper’s broader conclusion about present-day dollar dominance

Implications: The findings suggest the Fed’s actions reverberate globally, while many countries retain less monetary independence than assumed. The dollar’s dominance is durable, but it also raises Triffin-style sustainability risks and keeps fiscal policy relevant when exchange rates are rigid.