Every month the Bureau of Labor Statistics (BLS) tracks the prices of more than 80,000 goods and services and distills them into one number, the Consumer Price Index (CPI), but upon release, a lot of people don’t believe it. The CPI continues to be a testament to the art of economic spin. Since wages, social security cost of living increases and some agency increases are tied to CPI the government has a vested interest in keeping it as low as possible.
Composition of the market basket: The prices of the various goods and services that make up the CPI are weighted according to a standard market basket that represents the way people spend based on the Consumer Expenditure Survey. The category weightings are as follows:
Food and beverages |
15% |
Housing |
43% |
Apparel |
4% |
Transportation |
17% |
Medical care |
6% |
Recreation |
6% |
Education and communication |
6% |
Other goods and services |
3% |
If spending patterns diverge from these weightings, individuals may perceive inflation to be higher or lower than the reported CPI. For example, if a family spent more than the standard allocation of 6% on medical care, their own personal inflation rate could be higher than the stated CPI.
One component of the market basket – housing – warrants additional scrutiny. The “shelter” component of housing represents 32% of the total CPI index. CPI calculations use implied rent figures when computing housing costs, rather than the cost of home ownership. Until recently, home prices rose dramatically while rent costs lagged, leading some economists to believe that the CPI was understating the true rate of inflation. With the recent decline in housing prices and home equity, homeowners who can no longer afford their homes may be forced to rent, forcing rental rates higher, and possibly having a dramatic effect on the CPI.
In many respects, the cost of energy –specifically oil- attracts the most attention for consumers. With oil prices at all-time inflation-adjusted highs, many consumers are fearful of the effect this will have on their budgets. But automobile gasoline represents just 4.4% of the CPI, while public transportation represents 1.1%, and household fuel oil is a mere .2%. So the direct effect of increases in oil prices will not substantially impact the CPI.
The composition of the CPI market basket is adjusted infrequently, sometimes at intervals as long as ten years. In 1998 several changes were made to the way the CPI is calculated. One of these changes relates to the way people shop. Instead of buying the same item every week, they might be alert to temporary price hikes and substitute a cheaper item when possible. If their favorite brand of ice cream is more expensive than usual, for example, they might switch brands, buy it at a different store, buy a smaller size, or settle for a different dessert. This substitution adjustment has the effect of lowering the CPI, compared to using prices for the same items every week.
It is easy to see that the CPI calculation is far from perfect. Aside from the shortfalls I’ve described above, it also does not capture increases in taxes and fees. So as items like property tax, title fees and sales tax increase, the CPI will stay the same.