I don't know exactly, but when I visited Japan a year ago, I was struck by how inexpensive and high-quality everything was compared with the US and Canada. Japanese inflation and interest rates both remained very low for decades, while inflation has been extremely high in North America, and yet in terms of exchange rate, North American currencies were getting much much stronger relative to the yen. When you think about it, this is actually very weird.

Imagine that in 2012, $1.00 = 100 JPY and this buys the same tube of toothpaste in both countries. Then ten years later in 2022, that toothpaste still costs 100 yen in Japan, but costs $2.00 in the USA. Naively, you'd expect therefore that the yen has gotten more expensive, and the exchange rate to be around $2 = 100 yen, or else there's a major arbitrage opportunity for North Americans to buy Japanese toothpaste. (Imagine this is not just toothpaste, but virtually all consumer goods).

Then you find out that in fact, the exchange rate has gone the other way, where $1 USD buys something like 150 yen. Despite this, toothpaste is still 100 JPY in Japan, and $2 in the USA. How do you square this difference?

This doesn't necessarily bode well for the Japanese family or consumer (as their low prices may be a result of their low wages), but in terms of international competitiveness, it's a strong sign. It means that Japanese companies can make a killing on exports and tourism. From a mathematical standpoint, there are only two ways to balance this price difference: either Japanese productivity is much better than was previously priced-in, or else they have huge inflation coming shortly down the line. The former will be good for Japanese stocks and the latter case will be good for the yen (as the central bank would have to increase interest rates and/or sell US treasuries to protect the currency).