Inequality between world citizens in mid-19th century was such that at least a half of it could be explained by income differences between workers and capital-owners in individual countries. Real income of workers in most countries was similar and low. This was the basis on which Marxism built...

Population health tends to be better in societies where income is more equally distributed. Recent evidence suggests that many other social problems, including mental illness, violence, imprisonment, lack of trust, teenage births, obesity, drug abuse, and poor educational performance of...