https://taxfoundation.org/flat-tax-state-income-tax-reform/
https://cepr.org/sites/default/files/policy_insights/PolicyInsight92.pdf
https://knowledge.wharton.upenn.edu/article/why-are-the-markets-collapsing-how-bad-will-covid-19-really-be/?utm_source=kw_newsletter&utm_medium=email&utm_campaign=2020-03-17
https://www.socialeurope.eu/how-to-reform-the-european-fiscal-rules