Third, it is important to support the function of interbank markets to a certain degree by allowing arbitrage in interest rate transactions between banks holding current account balances at the BOJ and those without access to such accounts.
Such transactions also enable market interest rates to function relatively effectively as reference interest rates, which are conducive to various other related financial transactions and monetary policy judgments. 2 More importantly, the ECB faced a decline in some inflation expectation indicators and the accumulated disinflation risk in the second half of 2014, when a negative deposit facility rate was in place.