[THE INVESTOR] The shares of many countires' populations who are on middle incomes has fallen and particularly in advanced countries, statistics gathered by the Organization for Economic Cooperation and Development showed.
The share of South Korea's population that was in the middle income group -- defined as those with household disposable income of between 75 and 200 percent of the median -- came in at 60 percent, lower than the OECD average.
The middle income groups have been declining since 1980. Countries such as the United States, Germany and Luxembourg saw 5 percent declines in the shares of their populations that were in the middle income group in the 2000s.