https://www.nuffieldtrust.org.uk/files/2020-03/achieving-scale-and-spread-report-final.pdf
https://docs.prosperity.com/2916/0568/0539/The_Legatum_Prosperity_Index_2020.pdf
https://reutersinstitute.politics.ox.ac.uk/sites/default/files/2019-06/DNR_2019_FINAL_0.pdf
https://europepmc.org/article/MED/34757592#free-full-text