Working out who earns what is surprisingly tricky. Both the very rich, who sometimes try to keep their wealth from the taxman, and the very poor, who are sometimes mistrustful of clipboard-wielding officials, are especially hard to pin down. Nevertheless, before the covid-19 pandemic, household surveys consistently found a fall in the number of people living in poverty. The World Bank counted 659m living on less than $2.15 a day in 2019, down from around 2bn in 1990.
Yet this progress came at a cost: a global “precariat” emerged, members of which were barely out of poverty and perilously exposed to shocks, while the top 1% got rich faster. That, at least, is the received wisdom. The World Inequality Database, a project associated with Thomas Piketty and Gabriel Zucman, two economists, combines tax data with other sources of information to estimate the incomes of the uber-rich. They have found that although inequality between countries has fallen, as the rest has caught up with the West, within countries it may have risen. Chinese and Indian elites have done the best relative to their countrymen. American and European plutocrats, who are busy stashing wealth in tax havens, have done well, too.
A new paper by Maxim Pinkovskiy, Xavier Sala-i-Martin, Kasey Chatterji-Len and William Nober, economists at Columbia University and the New York branch of the Federal Reserve, challenges this picture. The researchers look at how likely people in different parts of the income distribution are to understate their income. They find that as the poor become richer, they become more likely to do so. Once adjustments are made for this, poverty has fallen faster than previously thought, and inequality within countries has not risen. It may even have fallen slightly.
To reach this conclusion, the authors look at the difference between estimates of income from regional household surveys and gross domestic product in the same area. When surveys imply that a region has less overall income than official figures, it suggests more income is going unreported. The researchers find that the richer an area, the larger the gap tends to be. This makes sense, notes Mr Sala-i-Martin. As a subsistence farmer becomes a small business owner or market trader, he develops more complex income streams and has more incentive to mislead the taxman.
If the finding holds, it changes the history of globalisation. Rather than a precariat, the researchers conclude that a “true global middle class” has emerged. Its members will not be plunged back into poverty by a financial crisis or a pandemic.
Yet the study will not be the final word. Economists have been arguing about trends in global inequality—and the quality of the data that lie beneath them—for decades. When it comes to the world’s richest people, the new research has more to say about the top 10% than the top 1%, who are widely believed to have done so much better than the rest. Like most papers, this one relies on assumptions that could be challenged by other researchers. Working out the global income distribution is one thing; convincing others you have the right answer is quite another. ■
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