An Ex-Post Empirical Investigation of the Efficacy of Central Bank Interventions in Currency Markets: Bilateral Exchange Rate of the Dollar

This paper investigates the role of central bank intervention in currency markets. Specifically, the bilateral exchange rates of the dollar versus the British pound, Swiss franc, and the yen are examined. Central banks conduct open market operations in order to regulate exchange rates in currency markets. The daily data and appropriate EGARCH models, which account for information asymmetry, provide the time varying volatility measures in the market for the three exchange rates. It is shown that the ex-post daily volatility in two out of three cases rises with central bank market interventions, while there is no statistically significant reaction in the daily volatility. Our findings suggest that rational expectations of currency traders may be responsible for these findings. Furthermore, our findings show that central bank expectations of intervention and reality of exchange rate behavior may be inconsistent.