The inflation rate measures the percentage growth of:
A) Real GDP from one year to the next.
B) The CPI from one year to the next.
C) Real GDP from the base period 1982-84 to a given year.
D) The CPI from the base period 1982-84 to a given year.
The Correct Answer and Explanation is:
The correct answer is B) The CPI from one year to the next.
The inflation rate is a measure that indicates how the general price level of goods and services in an economy is rising over time, typically from one year to the next. It’s essential to distinguish between measures of inflation and measures of economic output. Inflation focuses on price levels, while GDP (Gross Domestic Product) tracks the value of all goods and services produced in an economy.
The Consumer Price Index (CPI) is the most commonly used indicator to measure inflation. CPI tracks the average price changes over time for a specific “basket” of consumer goods and services, such as food, housing, clothing, transportation, and medical care. By comparing the CPI of one year to the CPI of the previous year, economists can calculate the inflation rate for that year. The formula to calculate the inflation rate using the CPI is:
[
\text{Inflation Rate} = \frac{\text{CPI in Current Year} – \text{CPI in Previous Year}}{\text{CPI in Previous Year}} \times 100
]
This percentage change represents how much prices have increased (or decreased) on average, reflecting purchasing power trends for consumers.
The CPI uses a base period (currently set at 1982-84 in the U.S.) where the index is standardized to 100, and future CPIs reflect price changes relative to this base. However, measuring inflation from the base period to a given year (as in option D) doesn’t capture the year-to-year inflation rate. Instead, option D reflects overall price change since the base period, not the annual inflation rate. Real GDP growth (options A and C) measures economic output, not price level changes, making them unrelated to inflation.
In summary, the inflation rate specifically measures the percentage growth in CPI from one year to the next, which makes option B the correct choice.