A reader of mine made a compelling point: Karl Marx believed that capital returns are diminishing, which would lead to ever greater degree of impoverishment of the working class. Marx claimed he “proved a logical necessity that in its development the general average rate of surplus-value must express itself in a falling general rate of profit.”
Thomas Piketty believes that capital returns are consistently high and perhaps even rising. He seems to be no less convinced about it than Marx about the opposite. His conclusion is that workers are going to be pauperised at an ever increasing rate.
Interestingly, Marx and Piketty start with very different assumptions, but still they come to the same conclusion: poor will be poorer. Both also propose a steeply progressive income tax structure as a remedy. (See Marx's Communist Manifesto, list of short-term demands, item #2.)
This is a truly socialist way of thinking. No matter what facts say, there's always the case for higher taxes.