The proportion of the developing worlds population living in extreme economic poverty fell from 28% in 1990 to 21% in 2001. Most of this improvement has occurred in East and South Asia.In 2012 it was estimated that, using a poverty line of $1.25 a day, 1.2 billion people lived in poverty. Given the current economic model, built on GDP, it would take 100 years to bring the worlds poorest up to the poverty line of $1.25 a day. UNICEF estimates half the worlds children (or 1.1 billion) live in poverty. The World Bank forecasted in 2015 that 702.1 million people were living in extreme poverty, down from 1.75 billion in 1990. Extreme poverty is observed in all parts of the world, including developed economies. Of the 2015 population, about 347.1 million people (35.2%) lived in Sub-Saharan Africa and 231.3 million (13.5%) lived in South Asia. According to the World Bank, between 1990 and 2015, the percentage of the worlds population living in extreme poverty fell from 37.1% to 9.6%, falling below 10% for the first time. During the 2013 to 2015 period, the World Bank reported that extreme poverty fell from 11% to 10%, however they also noted that the rate of decline had slowed by nearly half from the 25 year average with parts of sub-saharan Africa returning to early 2000 levels. The World Bank attributed this to increasing violence following the Arab Spring, population increases in Sub-Saharan Africa, and general African inflationary pressures and economic malaise were the primary drivers for this slow down.
Poverty levels can remain the same while those who rise out of poverty are replaced by others. The transient poor and chronic poor differ in each society. In a nine-year period ending in 2005 for the US, 50% of the poorest quintile transitioned to a higher quintile. Global prevalence
According to Chen and Ravallion, about 1.76 billion people in developing world lived above $1.25 per day and 1.9 billion people lived below $1.25 per day in 1981. In 2005, about 4.09 billion people in developing world lived above $1.25 per day and 1.4 billion people lived below $1.25 per day (both 1981 and 2005 data are on inflation adjusted basis). The share of the worlds population living in absolute poverty fell from 43% in 1981 to 14% in 2011. The absolute number of people in poverty fell from 1.95 billion in 1981 to 1.01 billion in 2011. The economist Max Roser estimates that the number of people in poverty is therefore roughly the same as 200 years ago. This is the case since the world population was just little more than 1 billion in 1820 and the majority (84% to 94%) of the world population was living in poverty. According to one study the number of people worldwide living in absolute poverty fell from 1.18 billion in 1950 to 1.04 billion in 1977. According to another study, the number of people worldwide estimated to be starving fell from almost 920 million in 1971 to below 797 million in 1997.