New Delhi, June 30 -- India's index of industrial production (IIP) data didn't always square with other readings that reflect the activity it covers, thus lending it an air of unreliability. Its out-of-date composition and other flaws meant it steadily lost value as a tracker. That, however, should change now that the index has been upgraded.

On 1 June, the government launched a new series with 2022-23 as its base year. On Monday, it replaced that with yet another version. The latest revision uses a newly crafted output producer price index as a deflator, instead of the wholesale price index, to strip out inflation while determining output changes.

This means the IIP now captures a superior snapshot of items whose output is reported by ...