In The Great Leveler, Walter Scheidel argues that over thousands of years, only mass violence and catastrophes have triggered significant reductions in inequality.
From the book’s introduction:
For thousands of years, civilization did not lend itself to peaceful equalization. … stability favored economic inequality. This was as true of Pharaonic Egypt as it was of Victorian England, as true of the Roman Empire as of the United States. … Four different kinds of violent ruptures have flattened inequality: mass mobilization warfare, transformative revolution, state failure, and lethal pandemics.
… there is no compelling empirical evidence to support the view that modern economic development, as such, narrows inequalities. There is no repertoire of benign means of compression that has ever achieved results that are even remotely comparable to those produced by the Four Horsemen.
In Taxing the Rich: A History of Fiscal Fairness in the United States and Europe, Kenneth Scheme and David Stasavage
explore the intellectual and political debates surrounding the taxation of the wealthy while also providing the most detailed examination to date of when taxes have been levied against the rich and when they haven’t. Fairness in debates about taxing the rich has depended on different views of what it means to treat people as equals and whether taxing the rich advances or undermines this norm. Scheve and Stasavage argue that governments don’t tax the rich just because inequality is high or rising—they do it when people believe that such taxes compensate for the state unfairly privileging the wealthy. Progressive taxation saw its heyday in the twentieth century, when compensatory arguments for taxing the rich focused on unequal sacrifice in mass warfare. Today, as technology gives rise to wars of more limited mobilization, such arguments are no longer persuasive. [Text from the Publisher’s website.]
Summary by Bryan Caplan:
Democracies have no inherent tendency to “soak the rich.”
Instead, democracies adopt high, progressive taxation in the face of compelling “compensatory” arguments for redistribution.
Only major wars of mass mobilization make compensatory arguments compelling.
Modern military technology has made majors wars of mass mobilization obsolete.
Therefore, tax the rich policies are a thing of the past, at least for developed countries. They won’t be coming back