The consumer price index (CPI) measures the average price of a cross-section of goods and services that people have purchased during a given time. It illustrates the purchasing power of a consumer dollar. However, because consumers change what they buy over time, changes in the CPI do not measure changes in the cost of living.

When our personal income is within the range of the CPI, our economy is growing. Our costs to buy things are equal to the money we earn.

The government uses the CPI to decide if new economic initiatives are required to prevent economic downturns, and to determine benefit levels for recipients of transfer payments.