that have financial system vulnerability. iii. policy issues concerning slow post - financial crisis recoveries thus far, i have explained the three issues central banks now face in the conduct of monetary policy. next, i would like to raise some policy issues from a longer - term perspective. in the wake of the global financial crisis, economic recoveries around the world have been modest relative to past recoveries despite the implementation of unconventional monetary policy. for the past year or so, academic and central bank circles have actively discussed how to interpret this fact. such discussions have been initiated by lawrence summers ’ revisit to the “ secular stagnation thesis ” advocated originally by alvin hansen in the late 1930s. various views have been raised regarding the causes of slow post - financial crisis recoveries ; for example, the persistent weakness on the demand side of the economy and the low productivity on the supply side. there have been wide - ranging interpretations and views on secular stagnation. in light of the discussions over slow post - financial crisis recoveries, i would like to raise three policy issues. the first issue is to what extent central banks should consider the impact on the supply side of the economy in conducting monetary policy. as a backdrop of the slow recoveries following the global financial crisis, it has been pointed out that the interaction between demand and supply has gained importance. that is, the weakness in demand impairs the supply side mainly by discouraging workers from participating in the labor market and dampening firms ’ investment in capital stock and in research and development. furthermore, a decline in expectations about future economic growth may cause insufficiency of demand. that said, the conventional view takes the supply side, such as the potential growth rate and the natural rate of unemployment, as a given in the conduct of monetary policy. how would the mechanism of slow recoveries affect such a conventional view? the second issue is with regard to what monetary policy tools are desirable under a low natural rate of interest. if the natural rate remains at a relatively low level over the medium to long term, compared with in the past, as suggested by the secular stagnation thesis, then the nominal interest rate is likely to stay around zero. furthermore, even after the normalization of interest rates, the nominal rate might fall back to zero or to a very low level. in that case, would unconventional monetary policy continue to be important even “ beyond the exit ”? moreover, would it eventually be regarded as conventional in an economy

in the night, which in turn explains why non - economists are often unaware of any microeconomic problems ’, avinash dixit ( 2014 ), microeconomics : a very short introduction, oxford university press, p. 2. such as, among others, the successful publication by william goetzman, money changes everything. how finance made civilization possible ( 2006 ) or the ‘ money and beauty ’ exhibition held in florence just over ten years ago. for the general point, see ogawa, masakata ( 2006 ), ‘ exploring possibility of developing indifferent public - driven science communication activities ’, journal of science education in japan 30. 4 ( 2006 ) : 201 - 209. one of the most recent books on the art of science popularisation offers a compelling comparison between the simplification required by popularisation in order to be understood by the lay public and heisenberg ’ s famous uncertainty principle, according to which whatever is gained by increasing the precision with which we measure the position of a particle is lost in terms of the accuracy with which we can measure its initial speed and vice versa. gouthier, d. ( 2019 ), scrivere di scienza. esercizi e buone pratiche per divulgatori, giornalisti, insegnanti e ricercatori di oggi, codice edizioni, torino pag. 51. scharrer l, rupieper y, stadtler m and bromme r. ( 2017 ), ‘ when science becomes too easy : science popularization inclines laypeople to underrate their dependence on experts ’, public understanding of science, 26 ( 8 ) : 1003 - 1018. doi : 10. 1177 / 0963662516680311. j. kruger and d. dunning ( 1999 ), ‘ unskilled and unaware of it : how difficulties in recognizing one ’ s own incompetence lead to inflated self - assessments ’, journal of personality and social psychology 77, 1121 ( 1999 ). francisco, frederico & goncalves - sa, joana ( 2019 ), ‘ a little knowledge is a dangerous thing : excess confidence explains negative attitudes towards science ’, ssrn electronic journal, 10. 2139 / ssrn. 3360734. roger penrose, la strada che porta alla realta ( the road to reality ), in the ‘ col