Why India Needs Better Numbers

When India reports new GDP numbers on Monday, there's likely to be cheer in New Delhi -- and not a little head-scratching. Last week, the Ministry of Statistics revised GDP figures for the financial years of 2012-13 and 2013-14 dramatically upward: Instead of growing at a tepid 4.7 percent in the year before Narendra Modi was elected prime minister, India supposedly grew at a roaring 6.9 percent pace.

Even some of the nation's most influential policymakers were taken aback by the new numbers, which were calculated using a different methodology, new sources of data and a new base year. Central bank governor Raghuram Rajan declared he wasn't ready to change his prediction for 5.5 percent growth this year, saying “I don’t want to say anything about the numbers until we understand them better." Arvind Subramanian, Modi's chief economic adviser, admitted he was "puzzled" by the new figures.