https://www.prospectmagazine.co.uk/wp-content/uploads/2017/12/Tooze_feature_app_1.pdf
https://www.piie.com/blogs/realtime-economics/if-markets-are-right-about-long-real-rates-public-debt-ratios-will
https://www.nber.org/system/files/working_papers/w27488/w27488.pdf