CPI: Consumer price index
The consumer price index (CPI) measures the average price paid by consumers for a specific basket of goods. The CPI is calculated by averaging the price changes of all the components of the basket in order to determine inflationary trends. It is the benchmark inflation index.

GNP/GDP implicit deflators
The GNP implicit deflator is calculated by dividing the current dollar GNP figure by the constant dollar GNP figure. The GDP implicit deflator is calculated by dividing the current dollar GDP figure by the constant dollar GNP figure. Both the GNP and GDP implicit deflators are released quarterly, along with the respective GNP and GDP figures. The implicit deflators are generally regarded as the most significant measure of inflation.

PPI: Producer price index
The producer price index (PPI) measures price changes in the manufacturing sector. There are three broad subcategories within the PPI which are generally used for economic analysis: crude intermediate and finished. The market tracks the finished goods index most closely, as it represents prices of goods ready for sale to the end user. The market places emphasis on the ‘core rate’ basket, excluding food and electricity, which are quite volatile and might obscure inflationary trends.