Wednesday, October 1, 2008

WPI vs CPI

Now as we have seen how inflation is calcualated with WPI , its now time to analyze wthether WPI is a good measure of inflation or not.

Most of the major economies like US, UK, Japan, France, Singapore and even our arch rival China have selected CPI as its official barometer to weigh its inflation. But our country, India, is amongst few countries of the world, which selected WPI as its official scale to measure the inflation in the economy.

The main difference between WPI and CPI is that wholesale price index measures inflation at each stage of production while consumer price index measures inflation only at final stage of production.

In last post we discussed about WPI, now let’s have a better understanding of CPI and how it’s better from WPI:

CPI is a statistical time-series measure of a weighted average of prices of a specified set of goods and services purchased by consumers. It is a price index that tracks the prices of a specified basket of consumer goods and services, providing a measure of inflation.
CPI is a fixed quantity price index and considered by some a cost of living index. Under CPI, an index is scaled so that it is equal to 100 at a chosen point in time, so that all other values of the index are a percentage relative to this one.

In use of WPI there are certain problems which have been encountered.
· Economists say that main problem with WPI is that more than 100 out of 435 commodities included in the index have abstained to be important from consumption point of view. Take, for example, a commodity like coarse grains that go into making of livestock feed. This commodity is insignificant, but continues to be considered while measuring inflation.
· WPI measures general level of price changes either at level of wholesaler or at the producer and does not take into account the retail margins. Therefore we see here that WPI does give the true picture of inflation.
· In present day service sector plays a key role in indian economy. Consumers are spending loads of money on services like education and health. And these services are not incorpated in calculation of WPI.
· Moreover the inflation figures that we get on Friday hardly makes a differnce to consumers, as the commodites on which inflation is calculated are not part individual consumers budget. Therefore in order to know what exact number of inflation is affecting your budget , it is advisible you should do your own calculation. You can compare your expenditure for previous years and with present scenario required to maitain your lifestyle and you ill come to know that increase in expenditure would be a few times higher than the official inflation figure.

But it is not easy for country like india to adopt to CPI , as in India, there are four different types of CPI indices, and that makes switching over to the Index from WPI fairly 'risky and unwieldy.' The four CPI series are:
· CPI Industrial Workers;
· CPI Urban Non-Manual Employees;
· CPI Agricultural labourers; and
· CPI Rural labour.
Apart from this official staements say that there is too much of lag in reporting of CPI numbers, which makes it difficult for india to calcualte inflation based on CPI figures.
India calcualtes inflation on weekly basis , whereas CPI figures are available on monthly basis. So all this give little ground for indian government to adopt CPI in calculating inflation.

Monday, September 29, 2008

How Inflation is measured

Thursday has become one of the most important days of our lives (at least for me). Well inflation figures come out and these numbers decide how every individual household budget would be like. But for many concept of inflation is just till the word “manghai badh gayi hai”. So I thought why not to discuss this interesting concept of manghai today:

What is inflation?
Inflation is the increase in prices of baskets of goods and services that represents economy as a whole. It is measured as an annual percentage increase. For e.g. We all love to watch movies; there was a time when movie ticket was for Rs 50 and now its cost Rs 100, the prices have doubled, this is how inflation affects us. Take another e.g. suppose with Rs 100 you can buy only 6kg of groceries , the same amount of money can only buy 6/ ( 1+I) kg of groceries next year , where I refers to rate of inflation beyond today. Thus if the rate of inflation is 5%, other things being equal you can buy only 6/1.05 worth of groceries.
Well all of us know what is inflation and what are its causes……..so I won’t be going much in to it….

Measurement scale of inflation
Inflation can be measured by the following 2 ways:
· Inflation based on changes in consumer prices for specific baskets of goods known as consumer price index (CPI).
· Inflation based on changes in average prices of goods traded in wholesale market called as wholesale price index (WPI)
In India inflation is calculated on the basis of WPI. WPI is calculated on weekly basis unlikely CPI that is calculated on monthly basis.
WPI in India includes a total of 435 commodities and tracks the change of prices in these commodities.
These goods can be classified as under:
· Primary articles ( food articles non-food articles and minerals)
· Fuel ,power ,light ,lubricants and manufactured products like food products , beverages , tobacco , textiles ,leather and leather products).
Now with one eg ill show how WPI is calculated
WPI is calculated on base year and WPI base year is assumed to be 100
Let’s calculate the WPI for year 2007: assume that price of kilogram wheat in 2007 is Rs 7 and for 1993-94 kilogram wheat costs Rs 5
Therefore the WPI of year 2007 is:
Price of wheat in 2007 – price of wheat in 1994 / price of wheat in 1994 *100
7-5 /5*100 = 40
Since WPI for base year is assumed to be 100, WPI for 2007 will become 100+40 =140.

Calculation of rate of inflation
If we have the WPI values of two time zones, say, beginning and end of year, the inflation rate for the year will be:

(WPI of end of year – WPI of beginning of year)/WPI of beginning of year x 100)
For e.g. WPI on 1st January 2007 are 141.2 and on January 2008 are 144.4, then inflation rate for year 2008 is,

144.4-141.2 / 141.2 *100 = 2.26 %, therefore we can conclude inflation rate for the year 2008 is 2.26% (I know this number seems to be unbelievable but it’s just an e.g.)

There is an on going argument that CPI is better than WPI and government should measure inflation with use of CPI…….for this wait for my next post……

Reference books
Macroeconomics by Campbell R McConnell and Stanley L Brue