1. The CPI and the Cost of Living
Outline
Index numbers
The Consumer Price Index (CPI)
The CPI and the Inflation Rate
Adjusting the money (nominal) wage for inflation using the CPI
The Costs of Inflation
Is the CPI accurate?
Consequences of overstating inflation

2. Index numbers
An index is a series of numbers used to track a variable’s rise or fall over time.
Index numbers are meaningful in a relative sense—by comparing one period’s index number with that of another period.
In general, an index number is calculated as:
Value of the measure in the current period
 100
Value of the measure in the base period

3. Example: Violent Acts on TV
We select the year 1996 as our base year, or benchmark period. In that year, there were 10,433 violent acts on TV. Thus, our index for the current year would be calculated as follows
Number of violent acts in the current year
 100
10,433
If there were 14,534 acts in 2000, then:
Thus, TV violence increased by 39.3 percent between 1996 and 2000.

4. Inflation
prices
Inflation is a sustained increase in the prices of goods and services (or the cost of living). To measure inflation, we look at changes in the price of a market basket of goods or services households typically purchase with their income
Time

5. The Consumer Price Index (CPI)
We use the CPI to measure changes in the cost of living experienced by households.
The CPI is the “narrow” price index in that the market basket used to construct it includes items purchased by households.
Bureau of Labor Statistics economic assistants check the prices of 80,000 items in 30 metropolitan areas each month.
The inflation rate is simply the percentage change in the CPI from one period to the next.
is the reference base period

6. The BLS now revises the market basket every 2 years

7. Calculating the CPI The CPI calculation has 3 steps
Find the cost of the CPI market basket at base period prices.
Find the cost of the CPI at current period prices.
Calculate the CPI for the base period and the current period.

8. (a) The cost of the CPI market basket a base period prices: 2000
CPI Basket
Cost of
Item
Quantity
Price
Oranges 10
$1 each
$10
Haircuts 5
$8 each
$40
Cost of the market basket at base period prices
$50

9. (b) The cost of the market basket at current period prices
CPI Basket
Cost of
Item
Quantity
Price
Oranges 10
$2 each
$20
Haircuts 5
$10 each
$50
Cost of the market basket at base period prices
$70

10. Computing the CPI Cost of CPI market basket at current prices CPI =
Cost of CPI market basket at base period prices
Thus for 2000 we have:
And for 2003 we have:

11. Consumer Price Index (1982-84 = 100)
Source:

13. The inflation rate
The inflation rate is measured by the percent increase in the CPI from one period (month or year) to the next.
To compute the inflation rate:
(CPI in the current year – CPI in the previous year)
Inflation rate =
CPI in previous year

14. To compute the 2002 inflation rate CPI Dec., 2001 177.3 Dec., 2002
181.6
Thus:
Inflation rate

15. On average, the prices of goods and services in the CPI market basket increased by 2.4% from 2001 to 2002

19. The inflation myth
Inflation cannot by itself decrease average real income. Inflation can shift purchasing power from some groups to others

20. Redistributive Costs of Inflation
Inflation in not an equal opportunity villain. That is, inflation arbitrarily, and unfairly, redistributes real income

21. The race to stay ahead of inflation
Inflation erodes the purchasing power of income and sets off a race to stay ahead of the cost of living.
Teachers, fireman, truck drivers, nurses, accountants, plumbers, social security recipients, and others strive to increase their incomes so as not to suffer a decrease in their standard of living.
Some groups do better than others.

22. were we better off in 2000 in terms of real purchasing power?
Seattle Transit Workers
Ave. Income of Seattle Transit Employees
The question is:
were we better off in 2000 in terms of real purchasing power?

23. Are Seattle transit employees any better off, at least based on these figures?

24. Why doesn’t Congress index the minimum wage to the CPI?
Why are we smiling? Because our social security benefits are indexed to the CPI
Why doesn’t Congress index the minimum wage to the CPI?

25. Value of the Federal Minimum Wage
Source: U.S. Department of Labor

26. Unexpected inflation redistributes real income from lenders to borrowers
Repayments schedules for most debt contracts are fixed in nominal or money terms—that is, debts are not indexed to inflation.
Inflation erodes the real value of repayments.
Savings & Loan institutions lost money on long term mortgages in the70s and 80s.

27. We bought this house in 1957 for $19,000
We bought this house in 1957 for $19,000. We financed the house on a 30 year mortgage note at 3.5 percent interest. Can you guess what our monthly payment was?
Answer: $85.32

28. Inflation undermines confidence in political leaders and institutions

29. Is the CPI accurate?
The Boskin Commission reported to Congress in 1996 that the CPI over-estimated the actual inflation rate in recent years by an average of about 1.1%. Many economists challenge the Boskin findings; however, most agree that inflation is overstated by the CPI

30. Sources of bias in the CPI
New Goods bias: New items such as cellular phones, pagers, and PCs enter the CPI market basket with a lag. The prices of these items has fallen as their popularity has risen.
Quality bias: For example, the CPI does not fully adjust for the fact car prices rise because of new features such as air bags and antilock brakes. Another example: the cost of hospitalization.
Substitution bias: People tend to substitute relatively cheaper items in place of those that have become relatively more expensive.
Outlet Substitution bias: People react to higher retail prices by shopping at the “big box” high volume discount retailers such as Wal-Mart and Home Depot. Also, internet shopping for airline tickets, hotels, and other items allows people to stretch their spending power.

31. What are consequences of overstating inflation?
Changes in real income over time are not measured properly.
Private contracts are distorted.
Increase in government outlays

32. This table indicates the average real wage decreased by about 10 percent between ’75 and ’95. But if the CPI has an upward bias of 1.1 percent per year, then the real wage actually increased by 11 percent during this period
Source: Department of Labor

33. We have a three-year contract with our hourly employees that is indexed to the CPI

34. Federal outlays indexed to the CPI include:
Benefits of 44 million social security recipients
Food stamps received by 22 million
Benefits received by 4 million retired military personnel and civil servants (or surviving spouses).