The inflation rate can be calculated for a given month or annual period; in either case, the appropriate new and prior period must be selected. The inflation rate is reported as a percentage and is often positive (assuming current market prices are appreciating).

Consumer Price Index (CPI) Categories

The monthly CPI release from the BLS leads with the change from the prior month for the overall CPI-U as well as its key subcategories, along with the unadjusted change year-over-year. The BLS's detailed tables show price changes for a variety of goods and services organized by eight umbrella spending categories.

Subcategories estimate price changes for everything from tomatoes and salad dressing to auto repairs and sporting events tickets. Price changes for each subcategory are provided with and without seasonal adjustment .

In addition to the national CPI indexes, BLS publishes CPI data for U.S. regions, sub-regions, and major metropolitan areas. The metro data is subject to wider fluctuations and is useful mainly for identifying price changes based on local conditions.

The table below represents the CPI basket weighted distribution for food, energy, and all other items.

How Is the Consumer Price Index (CPI) Used?

The CPI is widely used by financial market participants to gauge inflation and by the Federal Reserve to calibrate its monetary policy. Businesses and consumers also use the CPI to make informed economic decisions. Since CPI measures the change in consumers' purchasing power, it is often a key factor in pay negotiations.

The Federal Reserve

The Fed uses CPI data to determine economic policy. With a target inflation rate of 2%, the Fed may enact expansionary monetary policy to stimulate the economy should market growth slow, or enact contractionary monetary policy should the economy (and therefore prices) grow too quickly. In response to higher-than-desired inflation rates via the CPI, the Fed adjusts the Fed funds rate .

Other Government Agencies

The cost-of-living adjustments (COLAs) based on the CPI affect federal payments to the approximately 70 million Americans receiving Social Security and Supplemental Security Income (SSI) benefits. They also apply to federal pension payments, school lunch subsidies, and income tax brackets.

Housing

Mortgage rates (and other forms of long-term debt) are often impacted by rates set by government agencies. As the CPI increases and the government enacts policy changes to slow inflation, rates often increase. On the other hand, landlords may use CPI information to adequately assess what annual rent increases for renters should be.

Financial Markets

Financial market prices are driven by countless factors. One such factor is the CPI, as reactionary Fed policies directly impact economic growth, corporate profits, and consumer spending ability.

A higher CPI often means that a less stringent government policy is generally in place. This means that debt is often easier to obtain for cheaper and that individuals have greater spending capacity. On the other hand, lower or decreasing CPI may indicate that the government may ease policies that help boost the economy.

Labor Markets

The CPI and its components are also used as a deflator for other economic indicators, including retail sales and hourly/weekly earnings, to separate fundamental change from that reflecting change in prices. Employees may turn to CPI reports when approaching their employers for a raise based on nationwide increases in labor rates as well as pricing.

Be mindful that the CPI is published using national data, even though employees may be more suited to using local data to better understand their specific situation. In addition, some workers covered by collective bargaining agreements may have their contracts and wages tied to changes in CPI .