"However, in spite of the general perception that monetary policy should be conducted so as to avert deflation, a central bank cannot lower interest rates below the zero lower bound"

This quote by Toshihiko Fukui is referring to the basic assumption that monetary plan need to be conducted in order to avoid depreciation. Deflation is a decrease in the general rate degree of goods and also solutions, which can have an unfavorable impact on the economic climate. The quote is suggesting that, although it is generally accepted that financial policy needs to be utilized to stop depreciation, a central bank can not lower interest rates below the zero reduced bound. This indicates that, when interest rates are already at absolutely no, the reserve bank can not reduce them any further. This can be an issue, as it limits the ability of the reserve bank to stimulate the economic climate as well as avoid deflation. Therefore, it is necessary for reserve banks to consider other techniques of boosting the economy, such as quantitative easing, in order to stop deflation.