The subject was actively discussed in academia, and those supporting the independent tool theory argued that a tightening of window guidance could dampen the financial cycle, even if the official discount rate was held steady.5 The Bank of Japan, in the meantime, basically adopted the complementary tool theory and explained window guidance as a tool to support general policy instruments, such as changes to the official discount rate, rather than an independent policy instrument.
Notwithstanding such an official position, in the last half of the 1980s, as the call for international policy coordination necessitated the maintenance of a low interest rate environment with a view to expanding domestic demand, the Bank of Japan attempted to respond to signs of financial excesses through the tightening of window guidance.