Does reserve currency composition determine how exchange rates absorb US monetary shocks?
Core argument: Using high-frequency exchange rate data and reserve currency composition for 18 countries, the authors find US monetary policy surprises spill over to exchange rates through dollar liquidity and capital flow channels.
This paper shows that US monetary policy surprises exert significant spillover effects on exchange rate through dollar liquidity and capital flow channels. Using high-frequency exchange rate data and detailed currency composition of reserves for 18 countries, we show that estimated reserve-buffer effects depend on their composition. Dollar-denominated reserves substantially mitigate depreciation pressures, while non-dollar reserves have smaller estimated effects. Gold reserves are also associated with smaller exchange-rate responses, though less strongly than liquid FX holdings due to differences in immediacy and usability. Our results highlight an empirical complementarity between reserve holdings and access to international liquidity facilities such as central bank swap and repo lines. These arrangements are associated with a smaller role for reserve depletion during periods of dollar funding stress. Aggregate reserve size alone does not capture all dimensions associated with external resilience; currency composition and access to dollar liquidity facilities are empirically relevant for exchange-rate responses to US monetary shocks. These findings are consistent with recent large-scale purchases and sales of gold reserves by emerging economies amid sanctions-related restrictions and geopolitical concerns about access to dollar liquidity.




