FOR YEARS it has been a commonplace among those who watch China—and among those who lead it—that growing inequality is one of the greatest threats to the nation’s continued growth, development and stability. Nearly three years ago the premier, Wen Jiabao, promised both to make the “pie” of social wealth bigger, and to do a better job of distributing it. His government, he said, would “resolutely reverse the widening income gap”.

But for such an important issue, China has done a remarkably poor job of measuring and reporting on it. The Gini coefficient, a 101-year-old statistical tool that can be applied to many different indicators, is among the most widely used measures of income inequality around the world. Yet China went 12 years without formally disclosing its figures.

That changed last Friday, January 18th, when the National Statistical Bureau released a slew of data showing that China’s Gini number stood at 0.474 in 2012 (where a coefficient of zero would correspond to a perfectly equal society and a score of 1 would go to the society in which one person took absolutely everything). Though this is above the threshold of 0.4 that is sometimes reckoned to be a sign of potentially destabilising inequality, it is also down from the peak level of 0.491, recorded in 2008. These numbers put China in roughly the same range as America. There are plenty of countries that are more unequal than China, and still more countries that are less so.

But there are also plenty of serious questions about the accuracy of the newly released figures. In a blog post, a prominent Chinese economist, Xu Xiaonian, compared the newly reported Gini numbers to a “fairy tale”. Indeed, in Chinese policy circles, doubts the about methodological difficulties of calculating the Gini coefficient are not new, and have been cited as justification for China’s reluctance to report it.

Despite that official reluctance, hints and titbits have dribbled out before. Bo Xilai, the senior leader who was at the centre of last year’s most spectacular political scandal, used his final public appearance last March to reveal that China’s Gini coefficient had exceeded 0.46—and to suggest that increasingly concentrated wealth marked a failure of socialism.

Far more substantial than that last-ditch effort of a besieged politician was the academic study released in December 2012 which put China’s Gini number at an alarming 0.61, making it a contender for the dubious honour of nearly topping of the world’s inequality rankings (though still it would have fallen a good bit behind South Africa, which scores a contemporary world-beating 0.70).

If the official numbers released this week are to be believed, “Grandpa” Wen successfully kept his promise of three years ago and reversed a trend that was going the wrong way. But he took office nearly ten years ago, touting his determination to look out for China’s less-well-off. And the same set of official figures shows that income inequality is almost exactly where it was in 2003, recent reversals notwithstanding. The current premier is due to leave his post in March. Whichever estimate of China’s Gini coefficient is closest to the truth, there can be no doubting that his successor will have plenty more to do when it comes to distributing or redistributing that still-expanding pie.