Terms	Definition
Consumer Price Index (CPI)	The Consumer Price Index (CPI) measures the changes over time in the price level of consumer goods and services generally purchased by households. The year-on-year rate of change in the CPI is widely used as an indicator of the inflation affecting consumers.
CPI(A), CPI(B), CPI(C) and Composite CPI	Different series of CPIs are compiled by the Census and Statistics Department (C&SD) to reflect the impact of consumer price changes on households in different expenditure ranges. The CPI(A), CPI(B) and CPI(C) are compiled based on the expenditure patterns of households in the relatively low, medium and relatively high expenditure ranges respectively. A Composite CPI is compiled based on the overall expenditure pattern of all the above households taken together to reflect the impact of consumer price changes on the household sector as a whole.
Household Expenditure Survey	Based on the household expenditure patterns obtained from the Household Expenditure Survey (HES) conducted during October 2004 to September 2005, the C&SD has updated the base period and expenditure weights for compiling the CPIs.After rebasing, the CPI(A), CPI(B) and CPI(C) continue to reflect the price changes faced by households in the relatively low, medium and relatively high expenditure ranges respectively. Likewise, the Composite CPI continues to reflect the impact of the changes in consumer prices on the household sector as a whole. The expenditure brackets for the 2004/05-based CPI series are as follows : Approximate Average monthly percentage of household expenditure during Index households covered October 2004 to September 2005 CPI(A) 50% $ 4,000-$15,499 CPI(B) 30% $15,500-$27,499 CPI(C) 10% $27,500-$59,999 Composite CPI 90% $4,000-$59,999