beginner lesson • 10 min
Purchasing Power: What Your Money Can Buy
What you will learn
By the end of this lesson, you should be able to:
- Define purchasing power as the quantity of goods and services a unit of money can buy. - Explain why rising or falling prices generally change purchasing power. - Describe how the Consumer Price Index, or CPI, can be used to compare purchasing power across periods. - Recognize why a CPI-based average may differ from an individual household’s experience.
Evidence & citations7 sources
Purchasing power measures the quantity of goods and services that a unit of money can buy at a particular time. (supported)
When consumer prices rise, the purchasing power of a dollar generally declines; when prices fall, its purchasing power generally increases. (supported)
The Consumer Price Index measures the average change over time in prices paid by urban consumers for a market basket of goods and services. (supported)
A CPI-based comparison of purchasing power can be calculated using the ratio of price indexes for the two periods being compared. (supported)
CPI-based purchasing power is an average measure and may not match an individual household’s experience because households have different spending patterns. (supported)
Purchasing power in simple terms
Purchasing power is the amount of goods and services that a unit of money can buy at a particular time. If consumer prices rise, the same dollar generally buys less than before, so its purchasing power declines. If prices fall, the same dollar generally buys more, so its purchasing power increases.
Evidence & citations4 sources
Purchasing power measures the quantity of goods and services that a unit of money can buy at a particular time. (supported)
When consumer prices rise, the purchasing power of a dollar generally declines; when prices fall, its purchasing power generally increases. (supported)
A comparison across two periods
Imagine comparing what one dollar could buy in an earlier period with what one dollar can buy in a later period. If the CPI is higher in the later period, prices in the CPI’s market basket have generally increased, so the dollar’s purchasing power is generally lower. A CPI-based comparison uses the ratio of the price indexes for the two periods. The result describes the average change represented by that CPI measure, not necessarily the change experienced by every household.
Evidence & citations5 sources
When consumer prices rise, the purchasing power of a dollar generally declines; when prices fall, its purchasing power generally increases. (supported)
The Consumer Price Index measures the average change over time in prices paid by urban consumers for a market basket of goods and services. (supported)
A CPI-based comparison of purchasing power can be calculated using the ratio of price indexes for the two periods being compared. (supported)
CPI-based purchasing power is an average measure and may not match an individual household’s experience because households have different spending patterns. (supported)
Common misconceptions
**Misconception: Purchasing power is the same as the amount of money someone has.**
Purchasing power concerns what money can buy, not just the number of monetary units held.
**Misconception: A CPI-based purchasing-power measure describes every household exactly.**
The CPI measures an average change for a market basket associated with urban consumers. Households have different spending patterns, so an individual household’s experience may be higher or lower than the CPI-based average.
**Misconception: Any CPI comparison is automatically precise for every purpose.**
A CPI comparison should identify the relevant price index and the periods being compared. The result depends on the specific CPI measure used.
Evidence & citations6 sources
Purchasing power measures the quantity of goods and services that a unit of money can buy at a particular time. (supported)
The Consumer Price Index measures the average change over time in prices paid by urban consumers for a market basket of goods and services. (supported)
A CPI-based comparison of purchasing power can be calculated using the ratio of price indexes for the two periods being compared. (supported)
CPI-based purchasing power is an average measure and may not match an individual household’s experience because households have different spending patterns. (supported)
Key takeaways
Purchasing power measures how much goods and services a unit of money can buy at a given time. Price increases generally reduce the purchasing power of a dollar, while price decreases generally increase it. The CPI measures the average change over time in prices paid by urban consumers for a market basket of goods and services. Comparing CPI indexes can show an average purchasing-power change between periods, but different household spending patterns mean the result may not match everyone’s experience.
Evidence & citations7 sources
Purchasing power measures the quantity of goods and services that a unit of money can buy at a particular time. (supported)
When consumer prices rise, the purchasing power of a dollar generally declines; when prices fall, its purchasing power generally increases. (supported)
The Consumer Price Index measures the average change over time in prices paid by urban consumers for a market basket of goods and services. (supported)
A CPI-based comparison of purchasing power can be calculated using the ratio of price indexes for the two periods being compared. (supported)
CPI-based purchasing power is an average measure and may not match an individual household’s experience because households have different spending patterns. (supported)
Key term
**Consumer Price Index (CPI):** A measure of the average change over time in prices paid by urban consumers for a market basket of goods and services. It can be used as the basis for comparing purchasing power across periods.
Evidence & citations3 sources
The Consumer Price Index measures the average change over time in prices paid by urban consumers for a market basket of goods and services. (supported)
A CPI-based comparison of purchasing power can be calculated using the ratio of price indexes for the two periods being compared. (supported)
Knowledge check
Test what you just learned.
Complete this short assessment for Purchasing Power. You will get explanations immediately after grading.
Reference library