The Consumer Price Index (CPI) tracks the price of a market basket of goods and services purchased by U.S. households over time. Both monthly and annual changes are reported in the tables for the CPI in order to facilitate comparison with other series.
|Price Index (Jan-92=100)||Aug-02||Sep-02|
|Public transportation percent change from previous month||0.77||-0.91|
|All items percent change from previous month||0.33||0.17|
|All transportation percent change from previous month||0.39||0.26|
|Private transportation percent change from previous month||0.33||0.33|
|Price Index (Jan-92=100)||Sep-01||Sep-02|
|Public transportation percent change from same month previous year||-0.52||-2.87|
|All items percent change from same month previous year||2.59||1.52|
|All transportation percent change from same month previous year||0.45||-0.96|
|Private transportation percent change from same month previous year||0.40||-0.79|
NOTES: The consumer price index for a specific item is a weighted average of the prices for the individual components of the item. 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 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 out 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.
The base period of the original index is 1982-84. January 1992 is set to be the new reference point (=100) by dividing the values of the original index by the value of January 1992 in the original index. It is important to point out that this process changes only the reference point, and not the base period of the index because the weight structure of the index did not change.
SOURCE: U.S. Department of Labor, Bureau of Labor Statistics; October 21, 2002; available at: http://www.bls.gov/cpi/.