... process, see Bean (2001) and www.bankofengland.co.uk/monetarypolicy/ framework.htm These are published at www.bankofengland.co.uk Vol No Bank of England Interest Rate Announcements 217 Figure ... (1) where Δet is the change in the logarithm of the exchange rate at time t The mean of the exchange rate returns process, μ, the autocorrelation coefficient, ρ, and the variance of the innovation, ... various interest rate futures, and define their variable of interest as the deviation of the absolute value of exchange or interest rate returns in a given five-minute period on day j from the average...