Since the abandonment of the Bretton Woods system of fixed exchange rates in the early 1970s, exchange rates have displayed a surprisingly high degree of time-conditional volatility. This volatility can be explained statistically using autoregressive conditional heteroscedasticity models, but there remains the question of the economic source of this volatility. Central bank intervention policy may provide part of the explanation. Previous work has shown that central banks have relied heavily on intervention policy to influence the level of exchange rates, and that these operations have, at times, been effective. This paper investigates whether central bank interventions have also influenced the variance of exchange rates. The results from daily and weekly GARCH models of the $/DM and $/Yen rates over the period 1985 to 1991 indicate that publicly known Fed intervention generally decreased volatility over the full period. Further, results indicate that intervention need not be publicly known for it to influence the conditional variance of exchange rate changes. Secret intervention operations by both the Fed and the Bundesbank generally increased exchange rates volatility over the period.

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.

Foreign exchange intervention is frequently being used by central banks in countries which have a floating exchange rate. Most theoretical monetary policy models, however, do not take this phenomenon into account. This book contributes to close this gap between theory and practice by interpreting foreign exchange intervention as an additional monetary policy instrument for inflation targeting central banks. In-depth empirical analyses of the foreign exchange operations and interest rate policy of five inflation targeting countries (Australia, Canada, New Zealand, Sweden and the United Kingdom) demonstrate how foreign exchange intervention is used in practice.

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.

This paper analyzes whether and how central banks can use currency options to lower exchange rate volatility and maintain (implicit) target zones in foreign exchange markets. It argues that selling rather than buying options will result in market makers dynamically hedging their long option exposure in a stabilizing manner, consistent with the first objective. Selling a “strangle” allows a central bank to increase the credibility of its commitment to a target zone, and could have a lower expected cost than spot market interventions. However, this strategy also exposes the central bank to an unlimited loss potential.