A consumer price index (CPI) is a price index, the price of a weighted average market basket of consumer goods and services purchased by households. Changes in measured CPI track changes in prices over time. The CPI is calculated by using a representative basket of goods and services. The basket is updated periodically to reflect changes in consumer spending habits. The prices of the goods and services in the basket are collected monthly from a sample of retail and service establishments.
In economics, inflation is an increase in the general price level of goods and services in an economy. When the general price level rises, each unit of currency buys fewer goods and services; consequently, inflation corresponds to a reduction in the purchasing power of money. The opposite of inflation is deflation, a decrease in the general price level of goods and services. The common measure of inflation is the inflation rate, the annualized percentage change in a general price index.
A price index (plural: "price indices" or "price indexes") is a normalized average (typically a weighted average) of price relatives for a given class of goods or services in a given region, during a given interval of time. It is a statistic designed to help to compare how these price relatives, taken as a whole, differ between time periods or geographical locations. Price indices have several potential uses. For particularly broad indices, the index can be said to measure the economy's general price level or a cost of living.
In macroeconomics, inflation targeting is a monetary policy where a central bank follows an explicit target for the inflation rate for the medium-term and announces this inflation target to the public. The assumption is that the best that monetary policy can do to support long-term growth of the economy is to maintain price stability, and price stability is achieved by controlling inflation. The central bank uses interest rates as its main short-term monetary instrument.
Chronic inflation is an economic phenomenon occurring when a country experiences high inflation for a prolonged period (several years or decades) due to continual increases in the money supply among other things. In countries with chronic inflation, inflation expectations become 'built-in', and it becomes extremely difficult to reduce the inflation rate because the process of reducing inflation by, for example, slowing down the growth rate of the money supply, will often lead to high unemployment until inflationary expectations have adjusted to the new situation.
