During the past 15 years a new middle class has sprung up in emerging markets, producing a silent revolution in human affairs—a revolution of wealth-creation and new aspirations. The change has been silent because its beneficiaries have gone about transforming countries unobtrusively while enjoying the fruits of success.    

　　The new middle consists of people with about a third of their income left for discretionary spending after providing basic food and shelter. One of their most important characteristics is variety: middle-class people vary hugely by background, profession and income. As our special report in this week’s issue argues, their numbers do not grow gently, rising 2%, or 5%, or 10% a year. That happened in China about ten years ago. It is happening in India now. In emerging markets as a whole, it has propelled the middle class from a third of the developing world’s population in 1990 to over half today. The developing world is no longer simply poor.