(1)  Don’t take the central bank’s balance sheets as a measure of monetary easing  First, do not assume the size of the central bank’s balance sheets is indicative of the degree of monetary easing. Many unconventional policy measures are designed to be selective and are tailored to a specific market dysfunction. Thus, there is no common yardstick evaluating all market intervention.
Other options, such as PPI, GDP deflator and the index of per unit labor cost, are not widely accepted. Second, the calculation of real effective exchange rate has to deal with the time lag and availability of data, and price indices such as the CPI are subject to time lags and comparability.