For the first time, less than 10% of the world is living in extreme poverty

You raise another angle on wealth and income, and one that savvy researchers do look at. I don't know if development economists have a word for it, but I think of it as stability, or a non-monetary safety net.

I first was exposed to this idea in Kenya; a friend was losing his job, and I asked what his plan was, knowing that wages are low, and so on. He said worst case, he and his wife would move back to the family farm (un-mortgaged) and build out their cash crops.

Although his PPP-adjusted income was lower, lower middle class by American standards, he had something almost nobody under 50 in the 97th percentile has in America; a food and shelter safety net that was fairly resilient, and at the very least, not debt-ridden.

Situations like these are an inescapable consequence of population growth. As the number of humans increases, there will inevitably be less space allocated to inefficient activity, where efficiency is determined by an activity's contribution toward sustaining the larger population. Herding 63 sheep is not as efficient as housing 5000 people or stockyarding 500 pigs.

Growth is not 100% to blame, but growth is a sufficient cause for your story. It's worth tracking how well humanity copes with these inevitable changes.

That's an interesting point. I think that maybe what you're asking for is supplemental indicators such as number of people regularly getting the correct number of calories, have shelter, access to medical care and education. However, those supplemental indicators themselves don't tell you much about how much opportunity people have, of which economic indicators are a proxy for.

When I was young I remember most of my country was considered extreme poverty, but to be honest I was never really hungry, there was no people dying of hunger, people were happy and they appreciated little things. I would not like to see those times come back, but while it was difficult for everyone, it was easily survivable by just doing some jobs.

In real life, Tan Bao wouldn't have been evicted, he would have preferred the opportunity to accumulate money instead of not accumulating money, despite the temporary lower quality of life working in the factory. I'd say he has less poverty now. He can still survive but can also save.

I think they try to take in to account the income from farming to avoid that sort of miscalculation. Obviously there's a lot of leeway as to how to account for that stuff but anecdotally I think things have improved a lot. Especially in China. I was there around 1982 and people were living on gruel and breaking rocks with hammers to make a living, a bit like you'd imagine a prison gang. Now it's quite like the west in terms of living conditions for most.

You can actually buy 10lb / 5kg bags of rice for $5 in the US. http://www.walmart.com/ip/Great-Value-Long-Grain-Enriched-Ri...

That's enough for 50 servings, meaning you could feed yourself for $0.20 a day. Of course this ignores PPP, malnutrition and other factors, but don't underestimate how cheap food actually is.

It's $1.9 at purchasing-power parity, worldwide.

For example, in India $0.3 has about the same purchasing power as $1 in the US. US$1.9/day is thus about Rs 400/day in India, which is survivable. For example, a simple meal at a food stall will be under Rs 100.

The reason why it's $1.90 is because extreme poverty was pegged at a dollar per day by the World Bank in 1993 which has risen due to inflation to $1.90. There's nothing magical about the number, it simply provides a convenient baseline for comparisons to be made.

You forget that the US is an extremely expensive place to live relative to countries like India and China where enormous %s of the world population lives. $1.90 goes a long way in those places.

It depends on the living standards...

$1.9 doesn't afford you a comfortable life anywhere, but in the developing world, it's enough to not fear starvation. And that fear is a big part of being "extremely poor".

You'll have to google it for the different sides to the story and opinions on whether it should have been raised to $1.90, but here's a start -

http://blogs.worldbank.org/developmenttalk/international-pov...

PS You need to do the shopping, or learn to cook, $1.90 is very easy to feed people. But obviously it also about other things like food security and important stuff like happiness.

US is not the only country in the world...

> Why even have such a measure unless it's going to be at least $10/day as one likely needs at least that much just to feed themselves the cheapest possible food they can find.

Out of touch much? While studying, I fed myself with about $10-15 a week, and I ate better quality food than most people. I live in a place where food is more expensive than the US.

You can buy the calories you need per day for individual cents, if you buy potatoes in bulk. Above that, buy basic ingredients in large quantities, and you will have plenty of money left for fresh greens to top off you meals. Don't eat meat in every meal, and meat should always be a flavoring, not what makes up most of the meal.

I guess I could get by on $1.90 per day for food in the US if I had to, but it would really suck.

But the article is about extreme poverty. People who don't know if they're going to survive the next week or month. In the developing world, $1.90 per day provides just enough security that you're pretty sure you won't starve next week.

It's pretty damn bleak, but the fact is that a lot of people live in conditions where they know they may starve in the near future, and if fewer people live in those conditions, that's important.

Yes, it does: the graph says all figures are at 2011 PPP.

That would be currency, not money.