I was somewhat surprised by the following claims by Gregory Clark in A Farewell to Alms, A Brief Economic History of the World (2007):
the average person in the world of 1800 was no better off than the average person of 100,000 BC. Indeed in 1800 the bulk of the world’s population was poorer than their remote ancestors. The lucky denizens of wealthy societies such as eighteenth-century England or the Netherlands managed a material lifestyle equivalent to that of the Stone Age. But the vast swath of humanity in East and South Asia, particularly in China and Japan, eked out a living under conditions probably significantly poorer than those of cavemen. ... for the majority of the English as late as 1813 conditions were no better than for their naked ancestors of the African savannah.
So, would most economic historians agree with the above claims? Or have any openly disagreed with the above claims?