New CPI narrow for monetary policy decisions: Subbarao

The new series of consumer price index (CPI) is not enough for a robust statistical analysis of prices, Reserve Bank Governor D Subbarao said today.

He also said the new CPI has an excess focus on food prices, which has a 50 percent weight. House rents, which account for 10 percent, are also a cause for concern given doubts over the efficacy of the prices, he added.

"The new CPI has only 19 data points which is not sufficient for a statistically robust analysis," Subbarao, who demits office on September 5, said while speaking at the Statistics Day conference at the RBI headquarters here.

Posing the question if there is a case for shifting focus to the CPI, Subbarao said even in case of such an eventuality, the central bank will not abandon the wholesale price index (WPI) as a tool to monitor producer prices.

"My own view is we will not, because analytically we need to develop a series of producer price indices that will help us gauge how price momentum builds up in the economy."

Subbarao said RBI has traditionally focused more on WPI because of the deeper analytical insights it offers. "We've traditionally used WPI because we thought the legacy CPI is not representative enough for the entire population. WPI is more extensively researched by way of its empirical relationship with other variable like output, monetary aggregates and interest rates and presents richer analytical insight," he said, conceding that other central banks use CPI for policy formulation.

The new more inclusive CPI was introduced in 2011 and ever since that Subbarao has been repeatedly asked if the RBI will rely more on the new indice. His uniform response has been that the central bank uses all the available data points, including the CPI and WPI, in its policy formulation.

The wedge between the WPI and CPI number has consistently been high. For July, WPI came in at 5.71 percent while the CPI was still hovering around the double-digit mark.