With the aim of taking measures to bring about recovery following the economic recession after the burst of the bubble, the Bank gradually cut the policy interest rates. As a result, short-term interest rates reached approximately 0 percent at the end of the 1990s. However, at the same time, the potential growth rate became low, and accordingly the natural rate of interest declined.
This technology has become so ordinary that we forget just how revolutionary, and how new, it is. Thirty years ago, just as I was proceeding for my PhD, I would buy stacks of airmail envelopes, to communicate with my family back home. We spent weeks, even months, without hearing from each other, because of the difficulty and expense it took to  communicate.