The research classifies middle class people as people with discretionary income to spend on large consumer items such as refrigerators, washing machines or motorcycles, if they pay for entertainment, if they go on family holidays and if they have enough resources to withstand an economic shock, like  illness.

By this measure, 3.6 billion people are middle class.

By contrast, 3.1 billion people are economically vulnerable (living on $1.90 to $11 a day) and another 630 million are poor (living on under $1.90 a day). 

200 million people are rich, defined as living on $110 a day or more..

The researchers found that one person escapes extreme poverty every second, and five people a second are becoming  middle class.

By 2030, the researchers forecast that the number classed as rich will have grown to 300 million and the middle class will have expanded by 1.7 billion to 5.3 billion people. 

The number who are financially insecure or vulnerable will have shrunk to 2.3 billion and those in extreme poverty will have shrunk to 450 million.

Asia accounts for the improvement in living standards  with nine out of  ten of the new middle-class consumers predicted to be in China, India and south and east Asia.

“We are living through a landmark moment in human history: the first time since agricultural civilisation began when the majority of the world’s population does not live in considerable poverty,” says Kristofer Hamel, COO of World Data Lab, “while spending $11 a day or more may not seem like much to those who live in developed economies, crossing this threshold often constitutes the beginning of basic middle-class behaviour and lifestyle — having a basic standard of sanitation and healthcare, decent housing and the possibility of improved educational outcomes.”