Rules versus Discretion in Foreign Exchange Intervention: Evidence from Official Bank of Canada High-Frequency Data

This paper analyzes official, high-frequency Bank of Canada intervention and exchange rate data (the latter quoted at the end of every 5-minute interval over every 24-hour period) over the January 1995 to September 1998 time-period. The data is of particular interest as it spans over two distinctly different intervention regimes – one characterized by purely rules-based (“mechanistic”) intervention versus one characterized by both rules-based and discretionary intervention. This unique feature of the data allows for both a comparison of the effects of rules-based version discretionary intervention and a general investigation of intraday effects of intervention. Employing an event-study methodology and three different criteria for success, the study presents strong evidence showing that intervention systematically affects movements in the CAD/USD and in the desired direction along with some evidence that intervention is associated with a reduction of exchange rate volatility. Interestingly, there is no indication that discretionary intervention is more effective than rules-based intervention.