what is the consumer price index cpi 
cpi measures the prices of certain consumer goods and services over time to discern changes in prices that indicate inflation the prices for those goods and services are obtained from american consumers by way of the consumer expenditure survey conducted by the census bureau for the bureau of labor statistics which publishes cpi data the bottom linelong time investors know that loss of purchasing power can greatly impact their investments rising inflation affects purchasing power by decreasing the number of goods or services you can purchase with your money investors must look for ways to make a return higher than the current rate of inflation more advanced investors may track international economies for the potential effect on their long term investments 