This is a important point. Japan may follow suit if BOJ delays its change of stance in monetary management.
The Economist has long criticised Mr Greenspan for not trying to restrain the stockmarket bubble in the late 1990s, and then, after it burst, for inflating a housing bubble by holding interest rates low for so long (see article). The problem is not the rising asset prices themselves but rather their effect on the economy. By borrowing against capital gains on their homes, households have been able to consume more than they earn. Robust consumer spending has boosted GDP growth, but at the cost of a negative personal saving rate, a growing burden of household debt and a huge current-account deficit.