INFLATION

Inflation is defined as a sustained increase in the general level of prices for goods and services.

There are several variations on inflation:

• Deflation is when the general level of prices is falling. This is the opposite of inflation.
• Hyperinflation is unusually rapid inflation. In extreme cases, this can lead to the breakdown of a nation's monetary system. One of the most notable examples of hyperinflation occurred in Germany in 1923, when prices rose 2,500% in one month!
• Stagflation is the combination of high unemployment and economic stagnation with inflation. This happened in industrialized countries during the 1970s, when a bad economy was combined with OPEC raising oil prices.

Causes of Inflation

Demand-Pull Inflation - This theory can be summarized as "too much money chasing too few goods". In other words, if demand is growing faster than supply, prices will increase. This usually occurs in growing economies.

Cost-Push Inflation - When companies' costs go up, they need to increase prices to maintain their profit margins. Increased costs can include things such as wages, taxes, or increased costs of imports.

While leaving aside the debate on whether India should adopt CPI (Consumer Price Index), rather than the current WPI (Wholesale Price Index). Let’s find in detail how inflation rate is calculated in India; which is the WPI based inflation rate.

Mathematically, inflation or inflation rate is calculated as the percentage rate of change of a certain price index. The price indices widely used for this are Consumer Price Index (adopted by countries such as USA, UK, Japan and China) and Wholesale Price Index (adopted by countries such as India). Thus inflation rate, generally, is derived from CPI or WPI. Both methods have advantages and disadvantages. Since India uses WPI method for inflation calculation, let’s go in to the details of WPI based inflation calculation.

How is WPI (Wholesale Price Index) calculated?
In this method, a set of 435 commodities and their price changes are used for the calculation. The selected commodities are supposed to represent various strata of the economy and are supposed to give a comprehensive WPI value for the economy.

WPI is calculated on a base year and WPI for the base year is assumed to be 100. To show the calculation, let’s assume the base year to be 1970.

Let's calculate WPI for the year 1980 for a particular commodity, say wheat. Assume that the price of a kilogram of wheat in 1970 = Rs 5.75 and in 1980 = Rs 6.10

The WPI of wheat for the year 1980 is,
(Price of Wheat in 1980 – Price of Wheat in 1970)/ Price of Wheat in 1970 x 100

i.e. (6.10 – 5.75)/5.75 x 100 = 6.09

Since WPI for the base year is assumed as 100, WPI for 1980 will become 100 + 6.09 = 106.09.

In this way individual WPI values for the remaining 434 commodities are calculated and then the weighted average of individual WPI figures are found out to arrive at the overall Wholesale Price Index. Commodities are given weight-age depending upon their influence in the economy.

How is inflation rate calculated?
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 example, WPI on Jan 1st 1980 is 106.09 and WPI of Jan 1st 1981 is 109.72 then inflation rate for the year 1981 is,

(109.72 – 106.09)/106.09 x 100 = 3.42% and we say the inflation rate for the year 1981 is 3.42%.

Since WPI figures are available every week, inflation for a particular week is calculated based on the above method using WPI on the later week and WPI on the previous week. This is how we get weekly inflation rates in India.