The extensive use of the US dollar when firms set prices for international trade (dubbed dominant currency pricing) and in their funding (dominant currency financing) has come to the forefront of policy debate, raising questions about how exchange rates work and the benefits of exchange rate flexibility. This Staff Discussion Note documents these features of international trade and finance and explores their implications for how exchange rates can help external rebalancing and buffer macroeconomic shocks.

Milton Friedman argued that flexible exchange rates would facilitate external adjustment. Recent studies find surprisingly little robust evidence that they do. We argue that this is because they use composite (or aggregate) exchange rate regime classifications, which often mask very heterogeneous bilateral relationships between countries. Constructing a novel dataset of bilateral exchange rate regimes that differentiates by the degree of exchange rate flexibility, as well as by direct and indirect exchange rate relationships, for 181 countries over 1980–2011, we find a significant and empirically robust relationship between exchange rate flexibility and the speed of external adjustment. Our results are supported by several “natural experiments” of exogenous changes in bilateral exchange rate regimes.

Most trade is invoiced in very few currencies. Despite this, the Mundell-Fleming benchmark and its variants focus on pricing in the producer’s currency or in local currency. We model instead a ‘dominant currency paradigm’ for small open economies characterized by three features: pricing in a dominant currency; pricing complementarities, and imported input use in production. Under this paradigm: (a) the terms-of-trade is stable; (b) dominant currency exchange rate pass-through into export and import prices is high regardless of destination or origin of goods; (c) exchange rate pass-through of non-dominant currencies is small; (d) expenditure switching occurs mostly via imports, driven by the dollar exchange rate while exports respond weakly, if at all; (e) strengthening of the dominant currency relative to non-dominant ones can negatively impact global trade; (f) optimal monetary policy targets deviations from the law of one price arising from dominant currency fluctuations, in addition to the inflation and output gap. Using data from Colombia we document strong support for the dominant currency paradigm.

We provide evidence of a new channel through which exchange rates affect trade. Using a novel identification strategy that exploits firms’ maturity structure of foreign currency debt around a large depreciation in Colombia, we show that firms experiencing a stronger debt revaluation of dominant currency debt due to a home currency depreciation compress imports relatively more while exports are unaffected. Dominant currency financing does not lead to an import compression for firms that export, hold foreign currency assets, or are active in the foreign exchange derivatives markets, as they are all hedged against a revaluation of their debt. These findings can be rationalized through the prism of a model with costly state verification and foreign currency borrowing. Quantitatively, the dominant currency financing channel explains a significant part of the external adjustment process in addition to the expenditure switching channel. Pricing exports in the dominant currency, instead of the producer’s currency, mutes the effect of dominant currency financing on trade flows.

"Gross stocks of foreign assets have increased rapidly relative to national outputs since 1990, and the short-run capital gains and losses on those assets can amount to significant fractions of GDP. These fluctuations in asset values render the national income and product account measure of the current account balance increasingly inadequate as a summary of the change in a country's net foreign assets. Nonetheless, unusually large current account imbalances, especially deficits, should remain high on policymakers' list of concerns, even for the richer and less credit-constrained countries. Extreme imbalances signal the need for large and perhaps abrupt real exchange rate changes in the future, changes that might have undesired political and financial consequences given the incompleteness of domestic and international asset markets. Furthermore, of the two sources of the change in net foreign assets -- the current account and the capital gain on the net foreign asset position -- the former is better understood and more amenable to policy influence. Systematic government attempts to manipulate international asset values in order to change the net foreign asset position could have a destabilizing effect on market expectations"--NBER website

This paper assembles a comprehensive dataset of the currency composition of countries’ external balance sheets for 50 economies over the period 1990–2020. We document the following findings: (i) the US dollar and the euro still dominate global external balance sheets; (ii) there were striking changes in the currency composition across countries since the 1990s, with many emerging markets having moved from short to long positions in foreign currency, thus moving away from the so-called “original sin”; (iii) financial and tradeweighted exchange rates are weakly correlated, suggesting the commonly used trade indices do not adequately reflect the wealth effects of currency movements, and (iv) the large wealth transfers across countries during COVID-19 and the global financial crises increased global imbalances in the former, and reduced them in the latter.

The IMF’s 2019 External Sector Report shows that global current account balances stand at about 3 percent of global GDP. Of this, about 35–45 percent are now deemed excessive. Meanwhile, net credit and debtor positions are at historical peaks and about four times larger than in the early 1990s. Short-term financing risks from the current configuration of external imbalances are generally contained, as debtor positions are concentrated in reserve-currency-issuing advanced economies. An intensification of trade tensions or a disorderly Brexit outcome—with further repercussions for global growth and risk aversion—could, however, affect other economies that are highly dependent on foreign demand and external financing. With output near potential in most systemic economies, a well-calibrated macroeconomic and structural policy mix is necessary to support rebalancing. Recent trade policy actions are weighing on global trade flows, investment, and growth, including through confidence effects and the disruption of global supply chains, with no discernible impact on external imbalances thus far.