This paper presents a rule for foreign exchange interventions (FXI), designed to preserve financial stability in floating exchange rate arrangements. The FXI rule addresses a market failure: the absence of hedging solution for tail exchange rate risk in the market (i.e. high volatility). Market impairment or overshoot of exchange rate between two equilibria could generate high volatility and threaten financial stability due to unhedged exposure to exchange rate risk in the economy. The rule uses the concept of Value at Risk (VaR) to define FXI triggers. While it provides to the market a hedge against tail risk, the rule allows the exchange rate to smoothly adjust to new equilibria. In addition, the rule is budget neutral over the medium term, encourages a prudent risk management in the market, and is more resilient to speculative attacks than other rules, such as fixed-volatility rules. The empirical methodology is backtested on Banco Mexico’s FXIs data between 2008 and 2016.

We analyze the profitability of FX swaps used by the central bank of Brazil to shed light on the rationale for FX intervention. We find that swaps are profitable in expectation, suggesting that FX intervention is used to stabilize the exchange rate in the face of temporary excessive movements rather than to manipulate it away from fundamental values. In line with this interpretation, we find that the scale of FX intervention responds to the degree of exchange rate misalignment relative to UIP conditions. We also document that intervention is more aggressive when there is less uncertainty about the medium-term level of the exchange rate and when the exchange rate is overvalued rather than undervalued.

We study the effect of foreign exchange intervention on the exchange rate relying on an instrumental-variables panel approach. We find robust evidence that intervention affects the level of the exchange rate in an economically meaningful way. A purchase of foreign currency of 1 percentage point of GDP causes a depreciation of the nominal and real exchange rates in the ranges of [1.7-2.0] percent and [1.4-1.7] percent respectively. The effects are found to be quite persistent. The paper also explores possible asymmetric effects, and whether effectiveness depends on the depth of domestic financial markets.

The accumulation of large foreign asset positions by many central banks through sustained foreign exchange (FX) intervention has raised questions about its associated fiscal costs. This paper clarifies conceptual issues regarding how to measure these costs both from an ex-post and an ex-ante (relevant for decision making) perspective, and estimates both marginal and total costs for 73 countries over the period 2002-13. We find ex-ante marginal costs for the median emerging market economy (EME) in the inter-quartile range of 2-5.5 percent per year; while ex-ante total costs (of sustaining FX positions) in the range of 0.2-0.7 percent of GDP per year for light interveners and 0.3-1.2 percent of GDP per year for heavy interveners. These estimates indicate that fiscal costs of sustained FX intervention (via expanding central bank balance sheets) are not negligible.

During the twentieth century, foreign-exchange intervention was sometimes used in an attempt to solve the fundamental trilemma of international finance, which holds that countries cannot simultaneously pursue independent monetary policies, stabilize their exchange rates, and benefit from free cross-border financial flows. Drawing on a trove of previously confidential data, Strained Relations reveals the evolution of US policy regarding currency market intervention, and its interaction with monetary policy. The authors consider how foreign-exchange intervention was affected by changing economic and institutional circumstances—most notably the abandonment of the international gold standard—and how political and bureaucratic factors affected this aspect of public policy.