Establishing the threshold for determining when someone is middle class versus climbing out of poverty is difficult, particularly because the calculations rely on the use of purchasing power parity. Most new members of the middle class in 2030 will be at the lower end of the spectrum. Their per capita incomes will be still rated as “poor” by Western standards even though they will have begun to acquire the trappings of middle-class status. Growth in the number of those living in the top half of the range of this new middle class—which is likely to be more in line with Western middle-class standards—will be substantial, rising from 330 million in 2010 to 679 million in 2030. Much of the future global leadership is likely to come from this segment.