11  See Figure 1 in Shimizu, C., and K. G. Nishimura, “Biases in appraisal land price information: the case of Japan”, Journal of Property Investment and Finance, 24 (2006) 150–175. BIS Review 115/2010  9  they also suffered serious overcapacity and misallocation problems caused by the excessive optimism of the late 1980s and its subsequent collapse.
In retrospect, taking account of the devastating effects of excessive optimism and also the ineffectiveness of macro-prudential measures (in particular, window guidance as explained before), few would disagree that monetary policy should have played a role in attempting to rein in excessive optimism, provided that this had been detected at the time.