
https://www.boj.or.jp/research/wps_rev/wps_2021/data/wp21j07.pdf
https://i.imgur.com/KlbSWQq.png
https://www.jstage.jst.go.jp/article/jeps/18/2/18_1/_pdf
https://i.imgur.com/3950NuM.png
https://www5.cao.go.jp/j-j/wp/wp-je21/pdf/p01013.pdf
https://i.imgur.com/xjlTjss.png