I suspect the article is confusing cash and cash equivalents like savings accounts. It says that cash is 16% of the Japanese GDP. I have a hard time believing

I suspect the article is confusing cash and cash equivalents like savings accounts. It says that cash is 16% of the Japanese GDP. I have a hard time believing that. The Japanese have a high savings rate and the predominant means of saving is postal (government) savings accounts. (The last time I read about it was the middle of the last decade.) If I am correct, they are contemplating negative interests rates on savings accounts. They might be considering the elimination of cash to prevent people from pulling cash out of their savings accounts and putting it in their mattresses or lock boxes.