not by those at the bottom of the inverted pyramid of income, but of policies of governments.
In this Opinionator blog piece from the New York Times, the Nobel economic laureate takes us through the numbers.
He is exploring the work of World Bank economist Branko Milanovic and others, and starts with the development of the industrial revolution to provide historical context.
Consider this paragraph, focusing on the work of Milanovic:  
From 1988 to 2008, Mr. Milanovic found, people in the world’s top 1 percent saw their incomes increase by 60 percent, while those in the bottom 5 percent had no change in their income. And while median incomes have greatly improved in recent decades, there are still enormous imbalances: 8 percent of humanity takes home 50 percent of global income; the top 1 percent alone takes home 15 percent. Income gains have been greatest among the global elite — financial and corporate executives in rich countries — and the great “emerging middle classes” of China, India, Indonesia and Brazil. Who lost out? Africans, some Latin Americans, and people in post-Communist Eastern Europe and the former Soviet Union, Mr. Milanovic found.
Please keep reading.