Thursday, 15 September 2005 - 1:42 PM BST

I should clarify (one of those things I forget sometimes, because this is all very familiar to me), that $1 a day isn't just a measure of poverty, it's a measure of "extreme" poverty that's meant to function more at a global level. If you were to look into poverty lines for individual countries, most have a poverty line (or even an "absolute" poverty line) that's different from, and very often higher than, $1 a day, even in the "developing" world.

But even getting more specific about where the poverty line falls in a given country doesn't resolve the problem that the whole idea that there is such a thing as a "poverty line" tends to obscure the fact that there are people whose income varies above and below that line (so it's really less a poverty line than a "poverty zone"), as well as plenty of people living above the poverty line who are perpetually only one crisis away from dropping below it. If poverty is to be addressed in any meaningful way, their needs must be considered as well, but they may not come in for much attention since their situation isn't as dire as those living below the poverty line.

All in all, it's a pretty thoroughly flawed measure, and I really think that most of its appeal lies in the fact that it makes for cleaner soundbites and shorthand references to global poverty.