Column: Dogma-free models of inflation

Written by Surjit S Bhalla | Updated: Oct 14 2014, 07:47am hrs
Inflation data for September 2014 was released today and came in at 6.5%, and as such makes it the best reading since February 2008 when it registered 6%. Last October, the inflation gauge measured 10.2%. That is close to a 4 percentage point decline in one year. But I guarantee you that my brethren in the profession, and experts at RBI, will still be talking about how this declining inflation estimate is distorted, like many others this year, and how base effects, seasonals, etc, explain the entire reduction. And how, just you wait, inflation is going to shoot back up.

In a recent note the monetary experts at IMF argued that India needs to increase the repo rate in order to successfully reduce double-digit inflation. The target of inflation experts at RBI is 8% for December 2014. We all get our forecasts wrong every now and then but less than three months ago, the RBI experts were talking about the dangers of inflation not slipping below 8%. And just 10 days ago, RBI Governor Rajan talked about the dangers of inflation being above 6% fifteen months from now, in January 2016.

If RBI knows best about inflation, why is it consistently missing near-term forecasts, and missing them by a large margin One explanation for this is that it does not have a correct model of inflation or growth or a model relating the two. If this is true, why should RBI be trusted with its present model of inflation It could be that the RBI policy of substantially high repo rates is working to reduce inflation; however, the model needs to communicate the correct trend A miss by such a magnitude is a structural missremember, the informed RBI target for December 2014 is 8%. Three months from now, inflation is likely to be closer to 6%, not 8%.

But what is the correct model of inflation In several articles since July 2011, including (Monetary policy irrelevant for inflation,, I have argued the following: that a primary determinant of Indian inflation is the

policy variable of minimum support price (MSP) inflation set by the agriculture ministry. In addition, I have argued, indeed challenged, the monetary authorities and/or researchers to empirically document a relationship between any non-MSP variable and inflation.

So far this challenge has not been met. However, in an article written by a consultant to RBI (CAFRAL division), senior economist Amartya Lahiri without offering any alternative model of inflation claims that MSP inflation was just mirroring lagged CPI inflation. Technically, Lahiri does this by purging MSP inflation of past CPI inflation; interestingly, he does not do the counter purge. If he did it, as discussed below, he would not have obtained the result he did. (Indian Express, Dont blame MSP for inflation,

There are two major problems with Lahiris conclusion. First, at a conceptual and/or policy level, how can one argue that the politically- and Sonia Gandhi-inspired change in the terms of trade in favour of agriculture were all due to the fact that the UPA experts were just making up for past CPI inflation Just a simple check of the numbers would have shown Lahiri that he was following the wrong garden path. Secondly, I have argued, and still argue, that MSP affects inflation with a one-year lag. CPI inflation was averaging 4.5% for the nine years 1999 to 2007; and MSP inflation averaged 5.2%. In 2008, MSP was increased by 27%; and CPI inflation averaged 12.4% and 10.4% in the subsequent two years, and in double digits for each of the next three years. He should also note that CPI inflation is down in 2014, and likely to go lower, because MSP inflation has averaged less than 5% in 2013 and 2014.

Any knowledge of Indian policy-making would dictate that while past inflation is one of the factors entering into a policy makers mind, it is but one factor; others, especially vote-getting factors, are more important. One is tempted to add international food inflation as an additional factor determining MSP, and therefore, CPI inflation. But one should resist such temptations because international food prices go up and down. After all, when was the last time a policy-maker suggested a reduction in food procurement prices in India

Thankfully, we do not have to conduct casual empiricism in these matters. A Nobel prize winning economist CW Granger tackled this issue some 30 years ago and since then it is standard practice for graduate students, and most senior economists, to run these tests before they pronounce judgment on causality. According to Lahiri, past inflation causes MSP inflation, and MSP inflation does not cause future inflation. Interestingly, for the period for which we have both MSP and CPI (industrial workers) data, 1976-2013, the results are just opposite to those assumed by Lahiricausality tests indicate that while MSP causes CPI inflation, CPI inflation does not cause MSP inflation.

All these results, plus the data, have been posted in a blog (FAQs on Indian Inflation) on my website, For a total of 19 monetary and real variables (e.g. money supply growth, growth in mining output, fiscal deficit, rural wages, etc) two regressions were runthe first a simple regression between inflation and the determinant in question, and the second, a more correct estimation of the model with inflation as a function of lagged inflation (to control for persistence) and lagged determinant (what can the variable explain of inflation that is not accounted for by past inflation). Interestingly, only one determinant, among 19 contenders, is significant in the correct regressionMSP inflation.

In his thoughtful Statistics Day (September 25) speech, RBI Governor Rajan wondered aloud whether my results were affected by the use of strategic dummies. As the results in the blog make clear, the results are entirely unaffected by the use of any dummies or the lack thereof; and all the determinant tests reported were conducted without any dummies.

It is important that the determinants of inflation debate be carried out transparently, and to its logical end. Rajan states, citing my results, that if government-determined MSP drives inflation in India and nothing else, then forget expectations, forget output gap, and the whole exercise of monetary policy is pretty worthless and if that is so, then why doesnt RBI cut rates immediately The cutting rates part can come later, but for the moment, can RBI, or any RBI consultant, or any researcher prove a statistical link between inflation in India, and any monetary or interest rate, or output gap, or any variable besides MSP That would be useful to take the analysis and debate forward. And then we can talk about the desperate need of the Indian economy for lower interest rates. Considerable evidence exists that lower real rates help growthand considerable evidence exists that lower rates do not affect inflation in India. In this disinflation age, there is precious little evidence of lower interest rates affecting inflation anywhere.

Finally, Lahiri wants to shut up all commentators by appealing to authority, a well-known inductive fallacy. Here is how he concludes his article on my work: Intemperate and ill-thought-out assertions about the efficacy of monetary policy can unhinge private expectations of inflation. The RBI has been introducing a new monetary regime over the past year. The changes need time to work. It may be worth letting the experts do their job, rather than complicating matters by creating unnecessary confusion. (emphasis added).

The author is chairman, Oxus Investments, and a senior advisor to Zyfin, a leading financial information company. Twitter: @surjitbhalla