Relative deprivation

I just read an interesting article in the April 3, 2006 issue of the New Yorker on how the poverty level is defined in the United States (and elsewhere). The relatively simple familiar for the poverty threshold was established by creating a suggested diet for a family, calculating its cost, and then multiplying that value by three using government statistics indicating that families spend 1/3 of their income on food. Rather tautological. The article puts forth a new mechanism for defining poverty using "relative deprivation". Here, someone's poverty is related to the overall wealth of an area. I don't have time for a full exposition - jjust filing this for future reference.