Q. Explain Consumer Price Index?

CPI is a price index of a particular basket known as the CPI-basket. CPI-basket comprise essentially all the servicesand goods consumed in a country -gas,food, medicine, haircuts, house rent, transportation and so on. Composition of the CPI basket is determined by value of what is consumed in the country - the larger the value of entire consumption of a good or service, the larger the weight in basket. For illustration, if we spend twice as much on apples as on pears, apples would have twice the weight in the basket.  The particular details of the composition of basket and how the CPI is calculated are complex and vary somewhat between nations. Figure below demonstrates CPI for Germany after the reunification starting at January 1991. This data has 2005 as the reference year. This means that CPI is constructed in such a way that CPI is exactly equal to 100 on average during 2005.

Figure

Consumer price index (CPI) for Germany 1991 - 2010. Source: OECD.