[mitthrowaway2]

I'm not sure what you want a source for in particular, as it's a subjective statement; you can look here (https://www.stat.go.jp/english/data/cpi/1585.html) where the statistics bureau explains that prices are after-tax, and eg. here (https://tradingeconomics.com/japan/sales-tax-rate) for the tax rate over time. You can do the math to find the pre-tax CPI. You can look eg. here (https://www.rateinflation.com/consumer-price-index/japan-his...) for CPI figures going back farther, in particular 1992 being the end of the real estate bubble, where CPI was 94.2, basically identical with 2011's, where your source begins.

The widowmaker carry trade reflects the currency side, but what fascinates me is that for example, a tube of toothpaste (random example) has gone to $3~$4 in the US, while it's still $1 in Japan. Go to a dollar store in Japan (except for Daiso) and it's full of cheap, high-quality goods that are made-in-Japan, from plastic organizers and pencil cases to measuring tapes and bicycle stickers. Those are now cheaper than similar made-in-China products being sold in the USA. The cost of container shipping is still quite low. So you'd think Americans would be hungrily importing Japanese goods until the arbitrage opportunity disappeared, but they're just... not. And perhaps that reflects that the most significant and long-lasting component of inflation in the US is shelter, which can't be imported.