Consumer price indices for transportation, U.S. city average (Index: January 2004 = 100, seasonally adjusted)
|All items||Transportation||Private transportation||Public transportation|
NOTES: The Consumer Price Index (CPI) for a specific item is a weighted average of the prices for the individual components. The weights are determined by the expenditure shares of the individual components based on a survey of consumer expenditure during the base year(s). The CPI base year price is then normalized to 100. For some items, BLS establishes weights using several years of consumer expenditure surveys in order to smooth the effects of short-term price shocks and of the business cycle. Weights formed using several years will give a more accurate measure of typical consumer expenditure patterns.
Private transportation is a weighted average of the prices for new and used motor vehicles, motor fuels, motor vehicle parts and equipments, motor vehicle maintenance and repair, motor vehicle insurance, and motor vehicle fees (state and local registration and license fees, parking, and other fees).
Public transportation is a weighted average of the prices for airline fares, intercity bus fares, intercity train fares, ship fares, intracity transportation (intracity mass transit, taxi fares, and car and van pools), and other public transportation.
The base period of the original index is 198284. The new reference point, January 2004 = 100, has been set by dividing the values of the original index by the value of January 1998 in the original index. This process changes the reference point, and not the base period of the index because the weight structure of the index did not change.
The Consumer Price Index (CPI) tracks the price of a market basket of goods and services purchased by U.S. households over time.
SOURCE: U.S. Department of Labor, Bureau of Labor Statistics, Consumer Price Index, available at http://www.bls.gov/cpi/ as of December 2010.