104 The Consumer Price Index
Learning Objectives
- Use the Consumer Price Index (CPI) to calculate U.S. inflation rates
Now that we understand the mechanics of price indices and inflation rates, let’s look at the most commonly used price indices in the real world. In this section we will discuss the consumer price index. In subsequent sections we will examine the GDP deflator, the producer price index and others.
The most well known price index in the United States is the Consumer Price Index (CPI). When the rate of inflation is announced in the media, that rate is usually the percent change in the CPI. The CPI is calculated by government statisticians at the U.S. Bureau of Labor Statistics based on the prices in a fixed basket of goods and services that represents the purchases of the average family of four.
HOW DO U.S. GOVERNMENT STATISTICIANS MEASURE THE CONSUMER PRICE INDEX?
When the U.S. Bureau of Labor Statistics (BLS) calculates the Consumer Price Index, the first task is to decide on a basket of goods that is representative of the purchases of the average household. This is done by using the Consumer Expenditure Survey, a national survey of about 7,000 households, which provides detailed information on spending habits. Consumer expenditures are broken up into eight major groups, which in turn are broken up into more than 200 individual item categories. The BLS currently uses 1982–1984 as the base period.
The Eight Major Categories in the Consumer Price Index
- Food and beverages (breakfast cereal, milk, coffee, chicken, wine, full-service meals, and snacks)
- Housing (renter’s cost of housing, homeowner’s cost of housing, fuel oil, bedroom furniture)
- Apparel (men’s shirts and sweaters, women’s dresses, jewelry)
- Transportation (new vehicles, airline fares, gasoline, motor vehicle insurance)
- Medical care (prescription drugs and medical supplies, physicians’ services, eyeglasses and eye care, hospital services)
- Recreation (televisions, cable television, pets and pet products, sports equipment, admissions)
- Education and communication (college tuition, postage, telephone services, computer software and accessories)
- Other goods and services (tobacco and smoking products, haircuts and other personal services, funeral expenses)
For each of the 200 individual expenditure items, the BLS chooses several hundred very specific examples of that item and looks at the prices of those examples. So, in figuring out the “breakfast cereal” item under the overall category of “foods and beverages,” the BLS picks several hundred examples of breakfast cereal. One example might be the price of a 24-oz. box of a particular brand of cereal sold at a particular store. The specific products and sizes and stores chosen are statistically selected to reflect what people buy and where they shop. The basket of goods in the Consumer Price Index thus consists of about 80,000 products; that is, several hundred specific products in over 200 broad-item categories.