Up to December 2006, the same factor was applied to both lines. Since 2007, however, the indigence line has been adjusted to reflect changes in the food CPI, whereas the part of the poverty line that corresponds to non-food spending is adjusted by the relevant CPI. Since 2007, therefore, the differential between the indigence and poverty lines has ceased to be constant. In line with usual ECLAC practice, the data have been corrected to account for non-response to some income-related questions by wage earners, the self-employed and retirees, and to mitigate probable underreporting biases.