Should-Read: Peter H. Lindert: The Rise and Future of Progressive Redistribution: "Starting from today’s collection of estimates of fiscal distribution within each of 53 countries, we can begin mapping a history of... redistribution... http://piketty.pse.ens.fr/files/Lindert2017.pdf
...and... project some influences on its trends in the next few decades. There appears to have been a global shift toward progressive redistribution over the last hundred years in all prospering countries. The retreats toward regressive redistribution have been rare and have been reversed. As a corollary, the rise in income inequality since the 1970s owes nothing to any retreat from progressive social spending. Adding the effects of rising subsidy for public education on the later inequality of adult earning power strongly suggests that a fuller, longer-run measure of fiscal incidence would reveal a history of still greater shift toward progressivity, most notably in Japan, Korea, and Taiwan. The key determinant of progressivity in the decades ahead is population aging, not inequality itself or immigration backlash.