Deciding Who Counts as Poor

Any figure for the number of people living in poverty is the product of a definition, and the two definitions in general use answer different questions. An absolute line fixes a basket of goods judged necessary for survival and counts those who cannot afford it. A relative line takes a proportion of a country's median income and counts those below it.

[A] Each has a consequence its supporters would rather not dwell on. An absolute measure can record no poverty at all in a society where a large minority is excluded from anything an ordinary person does, since exclusion is not starvation. [B] A relative measure produces the mirror image: if every income in a country falls by a fifth in a single year, measured poverty may improve, because the median has fallen too. [C] Neither result is a mistake in the arithmetic; each follows exactly from what the measure was built to detect. [D] The reasonable conclusion is not that one line is correct but that a single number is being asked to do more work than any single number can do, and that publishing both is less a compromise than an admission of what the question actually contains.