Definition: World’s Middle Class

World’s Middle Class - "(1) countries with a real GDP per capita less than that of Italy and more than that of Brazil (Milanovic and Yitzhaki 2001), or (2) individuals with annual PPP incomes between $3,650 and $14,600 at 1993 prices (Bhalla 2002)." - source: Economic Development 4th Edition by E. Wayne Nafziger