This chart was created from a similar chart by economist Branko Milanovic. He analyzed global income inequality, comparing 1988 and 2008. His analysis indicated that the income of the global top 1% increased approximately 60%, while the income of the global middle classes rose 70-80%.[1][2] The chart is often referred to as the "Elephant curve" or "Elephant graph" because of a similarity to an elephant seen from the side.[3][4][5][6]