I participated in a panel discussion on the yen sponsored by the Foreign Correspondents Club of Japan. There was also discussion of Japan's growth prospects, the danger of a fiscal crisis, and other issues. Here's the gist of my opening presentation:

Even if the gap in US and Japanese interest rates were the only cause of the Japanese yen's weakness, there is little that Tokyo can do about it. The economy is too fragile to raise interest rates enough to substantially reduce the 4 percentage point gap. As seen in last Thursday's big leap, America's inflation figures have more power over the yen than anything the BOJ can do.
More importantly, the yen's historic low--the "real" is weaker than it has been in a half-century--reflects the dramatic deterioration of Japan's competitiveness. At any given gap in interest rates, the yen is 20 points weaker today than it would have been ten to 20 years ago. Even with a weaker yen over the past decade, Japan is still running chronic trade deficits whereas it used to run regular surpluses.
Worse yet, the weak yen is damaging the economy. It is reducing real wages and consumer purchasing power by causing big price hikes in import-intensive food and energy. 90% of the rise in prices over the past 18 months has come in food and energy. That kind of inflation transfers income from Japanese households to foreign producers.
What is required are reforms that improve Japan's underlying efficiency.

For further detail and a link to the video, see https://richardkatz.substack.com/p/yen-rate-tokyo-has-no-good-short

Richard Katz