"Extreme poverty" is defined on subsisting on less than $1.25.
According to Annie Lowrey, "The report contained a raft of statistics showing broad declines in poverty throughout the 2000s. For the first time since the World Bank started keeping statistics in 1981, poverty fell in every region of the world on a three-year timeframe. In sub-Saharan Africa, the proportion of the population living in extreme poverty fell below 50 percent for the first time. And between 1981 and 2008, poverty fell to just less than a quarter of the developing world's population from more than half."
The report cites improvement in the economies of China, Brazil and India as raising the income for their citizens, but that would not explain the major improvements in other poor areas, particularly sub-Saharan Africa, "where the proportion of people living in extreme poverty actually increased through the 1990s, before declining in the 2000s."
"Long-term changes are really starting to take hold", said Jeffrey Sachs, director of the Earth Institute at Columbia University and the United Nations' special adviser on the Millennium Development Goals, citing favorable market conditions, policies to tackle public health problems and technological change bringing tools like cellphones and Internet connections to even the most remote and rural areas.
"Separately, the United Nations announced that the world had met the Millennium Development Goal of halving the proportion of people without access to safe drinking water five years ahead of its 2015 target. Between 1990 and 2010, more than two billion people gained access to improved drinking water, according to a joint report by the United Nations Children's Fund and the World Health Organization. Now, 89 percent of the world's population has that resource, up from 76 percent in 1990," notes Lowrey.