The Guardian gets it wrong on absolute poverty

Having criticised The Economist for slipping into error on precisely two previous occasions, it only seems fair that I hold The Guardian to the same standard. Specifically, in an article published today about a new report from the Social Mobility and Child Poverty Commission, Patrick Wintour writes:

It also predicts that 2010-2020 will be the first decade since records began that saw a rise in absolute poverty – defined as a household in which income is below 60% of median earnings. A rise from 2.6 million households in absolute poverty to 3.5 million is now expected.

Unless I am mistaken, absolute poverty is not and has never been defined as "a household in which income is below 60% of median earnings". According to the United Nations, absolute poverty "measures poverty in relation to the amount of money necessary to meet basic needs such as food, clothing, and shelter", whereas relative poverty "defines poverty in relation to the economic status of other members of the society". Thus, "a household in which income is below 60% of median earnings" is quite clearly a definition of relative poverty. (The distinction between absolute and relative poverty is also recognised by the Joseph Rowntree Foundation.)

Incidentally, it is not obvious whether this error was originally made by the authors of the report themselves and then reproduced by Mr Wintour, or whether it was introduced by Mr Wintour de novo.