Nobel Prize Winners seem to have a habit of making bizarre claims that make you question whether they were really brilliant in the first place. Take Nobel Prize Winning Chemist Kary Mullis: after picking up a big cheque in Sweden, he went on to claim that HIV and AIDS weren't linked and that OJ Simpson was innocent. Or Nobel Prize Winning Physicist Brain Josephson who believes that psychokinesis is real and that water has 'memory'.

In a similar vein (although somewhat less severe), Nobel Prize Winning Economist Angus Deaton has written an essay attacking a view he dubs "Cosmopolitan Prioritarianism". Described by him as "an ethical rule that says we should think of everyone in the world in the same way, no matter where they live, and then focus help where it helps the most."

Most Cosmopolitan Prioritarians (of which I'd class myself, as well as my colleagues Sam Bowman and Ben Southwood), tend to be big fans of globalisation and free trade. While free trade benefits both developed and developing countries, it also reduces wages in places like Port Talbot, that are wealthy compared to India or Ghana but not by UK standards. But this is worth it for the truly breathtaking declines in extreme poverty in poor countries.

Now it's not unusual for an economist to bash globalisation, indeed since David Autor's paper on the effect of Chinese Imports on US labour markets, it's become the 'trendy' thing to do.

But, Angus Deaton goes further a makes a truly bizarre claim.

But several million Americans – black, white, and Hispanic – now live in households with per capita income of less than $2 a day, essentially the same standard that the World Bank uses to define destitution-level poverty in India or Africa. Finding shelter in the United States on that income is so difficult that $2-a-day poverty is almost certainly much worse in the US than $2-a-day poverty in India or Africa.

Citing research by Edin and Shaefer, here Deaton implies that there several million Americans who have substantially worse lives than Sub-Saharan Africans living in extreme poverty. This just doesn't pass the smell test.

Indeed, the ASI's own Tim Worstall already dealt with this rather misleading statistic back in September 2015.

They use an odd definition of income. One that doesn’t include all income in fact. They look only at cash income. But the US spends $500 billion a year on things like Medicaid and other health care services for poor people. That’s obviously got to be part of poor peoples’ incomes as well then. And then there’s Section 8 housing vouchers which pay for habitation for many poor people. This is also excluded. In their most restrictive version of income they don’t even include Food Stamps.

So what they’re really measuring is the cash incomes of the poorest people without accounting for pretty much all the things that are done to increase the total incomes (such total income being equal to consumption possibilities of course) of those poor people.

And that’s where their large rise in this form of poverty comes from. They are, as above, measuring only the cash income of poor people, including cash from welfare. But this system was deliberately changed in the 1990s to reduce the amount of cash welfare people got and increase the amount of in kind welfare (ie, Section 8, EITC, SNAP and so on) that people got.

But that's not all, there's even more reasons to doubt this zombie stat. First, the survey Edin and Shaefer use to compile their data systematically underestimates the benefits received by poor Americans.

Second, a whole bunch of people list their income as $0 in the survey, which given that it's nigh-on impossible to live on $0 worth of resources, suggests that there are serious measurement errors.

Indeed, when the Brookings Institute put the numbers under scrutiny, they found that virtually no Americans were living on under $2 a day.

It's certainly true that many Americans are struggling so far, and we probably do more to compensate those who've gained less from globalisation (perhaps with a Negative Income Tax). But when Deaton says "perhaps it is not so clear that the greatest needs are on the other side of the world." He's simply wrong.