http://www.ecb.europa.eu/pub/pdf/other/ebart201703_01.en.pdf
https://socialeurope.eu/a-european-solidarity-pact
https://cepr.org/sites/default/files/policy_insights/PolicyInsight92.pdf
https://www.brookings.edu/articles/the-difference-in-how-the-wealthy-make-money-and-pay-taxes/