All About the Consumers Price Index (A Layperson's Guide) is a user-friendly guide to explaining the background and uses of one of New Zealand's best known statistics, the Consumers Price Index (CPI).
The CPI provides a measure of change in the prices of goods and services bought by households. It also provides a measure of inflation and therefore plays a crucial role in the setting and monitoring of monetary policy. In addition it is used to adjust benefit payments and in wage negotiations.
The CPI is regularly reviewed and the latest review was effective from the September 1999 quarter. This publication is valuable to all those who are seeking an understanding of this key economic statistic.
Published 1 February 2000
As a printed paper version
Catalogue Code 18.041.2000
ISSN 0-478-20748-4
Price, per title $9.95
Part 1 - What is the CPI?
New Zealand, like other countries, needs a general measure of the rate of price change of the goods and services purchased by households. The Consumers Price Index (CPI) is used for this purpose.
The simplest way to think of this is as a measure of the total cost of goods and services purchased by New Zealand consumers. Price changes of particular goods and services will alter the total cost. The Consumers Price Index measures this change over time.
Using a more precise definition, the CPI measures the changing cost over time of the goods and services purchased in New Zealand in a specified base period by private, New Zealand-resident households, regardless of the location of the supplier.
Where possible, prices are collected for exactly the same goods and services each period. This ensures that changes in the cost of the goods and services shown by the CPI are not due to changes in the quantity or quality of the goods and services purchased. The CPI reflects only "pure" price changes.