The Consumer Price Index (CPI) is a measure
of the average change in prices over time in a fixed
market basket of goods and services. The Bureau
of Labor Statistics publishes CPI’s for two
population groups: (1) a CPI for All Urban
Consumers (CPI-U) which covers approximately
89 percent of the total population and (2) a CPI for
Urban Wage Earners and Clerical Workers (CPI-W)
which covers 28 percent of the total population.