When More Dollars Buy Less Understanding Purchasing Power
A bigger paycheck or savings balance can look like progress. Find out whether it buys more by comparing the numbers with the prices of everyday goods and services.
Can a Pay Rise Leave You Buying Less?
The dollar amount tells only part of the story. Purchasing power tells us what that amount can buy.
Compare two wage paths in the Purchasing Power Simulator, or use an unchanged shopping basket to test a larger paycheck on paper. Then explore what happens to savings when interest and prices grow at different rates.
Designed for homeschooling, summer learning, classroom enrichment, and library groups. Choose one activity for the short session. Historical data, documentary viewing, and assessment are optional extensions.
Look Beyond the Balance
Distinguish the number of dollars from what those dollars can purchase.
Compare Pay With Prices
Test whether income and savings keep pace with the same basket over time.
Check the Measure
Ask which prices, dates, and households a comparison actually represents.
Teach It Online or on Paper
Choose an activity and use the printable materials attached to this topic.
Prepare the Activity
Suggested level: Ages 13–18, introductory. Basic reading and division are enough for the core activity. Percentage calculations are optional. Either route works with one adult and one learner.
Time: Prepare for 5–10 minutes. Allow 15 minutes for one core route, discussion, and an exit sentence. Add 5–10 minutes for savings or assessment, 15–20 minutes for the historical calculator, or viewing and reading time followed by 15–20 minutes for the documentary worksheet.
Online route: Use student pages 1 and 3, a connected device, pencil, and the Purchasing Power Simulator. Enter the starting settings before teaching.
Paper route: Use student pages 2 and 3, pencil, and a calculator. No internet or personal financial information is needed.
Curriculum connection: Pack 03 and Money vs. Currency introduce purchasing power. Pack 04 explores income and price timing. This pack adds measurement, with Nominal Confusion as extended reading.
Count What It Buys
The number of dollars is one measurement. What those dollars buy is another. A bigger paycheck can buy less if prices rise faster than pay. A savings balance can grow through interest while losing purchasing power.
To compare fairly, use the same period and the same basket of goods and services. A nominal amount is the number in current dollars. A real amount adjusts for the change in the chosen price measure.
Predict, Compare, and Explain
0–2 minutes · Predict.
Can your pay rise while what it buys falls? Record a reason.
2–4 minutes · Introduce.
Read the explanation above and introduce one activity.
4–9 minutes · Compare.
Run A and B online, or calculate what monthly pay and an unchanged $100 can buy on paper.
9–13 minutes · Discuss.
Work through the three questions below. Oral answers are fine.
13–15 minutes · Explain.
Complete the exit sentence and revisit the prediction.
Same Prices. Two Wage Paths.
Use student page 1 and open the Purchasing Power Simulator. These are illustrative model inputs.
Choose Open Laboratory. Set Annual Income to $60,000; Cash Savings to $25,000; Annual Price Inflation to 5%; Annual Wage Growth to 2%; Savings Interest Rate to 1%; and Time Horizon to 10 years.
Select Run Purchasing Power Analysis. Record the future nominal income, real income change, cost of the $100 basket, and purchasing power of an unchanged $100. Use end-of-horizon results; set the timeline to year 10 if reading it.
For Run B, change only Annual Wage Growth to 5%. Run the analysis again and record the same results. What changed, and what stayed the same?
Compare future nominal savings with their purchasing power in today’s dollars. Why do the savings results remain the same in both runs?
Model limits: Constant annual rates, no additional savings contributions or withdrawals, and no taxes or fees. The comparison illustrates a mathematical relationship; it is not a forecast.
The Same Basket, a Bigger Paycheck
The fictional example: One year ago, an unchanged basket of goods cost $100. Today it costs $125. Monthly pay rises from $1,000 to $1,100. We compare buying capacity; nobody has to spend the whole paycheck.
Basket price: $100
Monthly pay: $1,000
How many basket-equivalents can this pay buy?
Basket price: $125
Monthly pay: $1,100
How many basket-equivalents can the new pay buy?
Calculate: Basket-equivalents = dollars available ÷ basket price. Fractions are allowed: 2.5 means the buying capacity of two and a half baskets. Complete the pay row on student page 2, then compare what an unchanged $100 can buy before and after.
Explain: Has pay increased in dollars? Has its buying capacity increased? Use the quantities to support your answer.
Optional savings: A $500 balance earns 5% interest and becomes $525 over the same year. No deposits or withdrawals are made. Compare the basket-equivalents it buys before and after.
Optional percentage challenge: Calculate the percentage rise in the basket price and the percentage fall in what an unchanged $100 buys. Why are they different?
Assumptions: The basket’s contents and quality stay fixed; taxes and fees are excluded. The price increase is invented and does not establish what caused inflation.
Three Questions to Work Through
Use student page 3 and support your explanation with the activity.
Separate the dollar amount from what it can purchase. Use one result from your chosen route.
Explain what must match, using the same period and comparison basket.
Give one reason and one piece of information needed to compare two households.
A larger dollar amount does not necessarily mean … To find out whether I can buy more, I need to compare …
Check Your Understanding
A. In a new example, the same basket rises from $100 to $110 and pay rises from $1,000 to $1,100. Compare how many baskets each paycheck buys.
B. Prices rose 5% last year and rise 2% this year. Are prices now falling? Explain. Optional: calculate the cost of an initially $100 basket after both years.
Compare the Measures
Use student page 4 and the Inflation Calculator. Set Starting Amount to $100, From to 2001, and To to 2024.
Run the calculation for CPI-U, AIER Everyday Price Index, and LISEP True Living Cost. Record each equivalent 2024 amount, cumulative price change, and the date checked.
Read the notes on baskets and populations. This calculator uses January observations for CPI-U and EPI but annual estimates for TLC. Discuss how those differences affect the comparison and which measure may be relevant to a particular household.
Then select M2 Monetary Inflation. Explain why retaining the same proportional share of a money stock is different from buying the same basket of goods. M2 growth is not itself a consumer price inflation rate.
Arithmetic check: For an equivalent amount E, the cumulative price rise is (E ÷ 100 − 1) × 100%. The buying power of an unchanged $100, in starting-year dollars, is 10,000 ÷ E. Apply this check to the price measures.
Watch, Read, and Check a Claim
Watch: Hidden Secrets of Money, Episode 1: Money vs. Currency. Preview it before teaching; assign the full film or a checked excerpt. Allow viewing time separately.
Read: In the second post of Nominal Confusion, read What Is Nominal Confusion? and The Real Return Calculation. Allow reading time, then 15–20 minutes for student page 5.
1. Locate: Paraphrase a film claim about storing value or purchasing power. Record actual start and end timestamps. Is it a definition, a historical claim, or a prediction?
2. Test: Which dated prices, wages, or other records could support or challenge the claim? Why can a classroom model alone not establish a historical result?
3. Calculate: A savings balance rises 8% while a comparison basket rises 6%. Calculate (1.08 ÷ 1.06 − 1) × 100% and explain the result.
4. Reconsider: What would you now explain differently about a larger paycheck or balance? Name a question you still want to investigate.
Check the Buying Power
Paper route: Monthly pay buys 10 baskets before and 8.8 after. The new pay is worth $880 in starting-year dollars, a 12% real decline despite a 10% nominal rise. An unchanged $100 buys 1 basket before and 0.8 after.
Savings: $500 buys 5 baskets before; $525 buys 4.2 after. The new balance has $420 of starting-year purchasing power, a 16% real decline. The basket price rises 25%, while the buying power of unchanged cash falls 20%.
Simulator, Run A: Independently calculated year-10 income is $73,139.67, worth $44,901.41 in starting-year dollars: a 25.16% real decline.
Simulator, Run B: Income is $97,733.68, worth $60,000 in starting-year dollars: no real change. In both runs, the original $100 basket costs $162.89, and unchanged $100 has $61.39 of starting-year buying power.
Simulator savings: Both runs produce $27,615.55 nominal savings, worth $16,953.55 in starting-year dollars. The teacher PDF gives the formulas. These are calculated expectations for the specified settings; allow for interface rounding.
Discussion: Compare growth in dollars with prices over the same period. Equal growth preserves buying power in the simplified model. Household budgets and price experiences differ; a national index is an average.
Assessment: A: both paychecks buy 10 baskets. B: prices are still rising, just more slowly; this is disinflation. The two-year basket costs $107.10. The documentary calculation gives about 1.89% real growth.
Teaching precision: The exercises show how to adjust a dollar amount for prices. They do not establish a cause of inflation, a historical conclusion, or a forecast. The film and curriculum use a particular distinction between money and currency; standard economics also commonly includes bank deposits within money. Define terms before evaluating claims.
Download the Student and Teacher PDFs
The two PDFs attached to this topic are ready to print. Keep the answer guide separate from the learner’s pages.
Online comparison, paper activity, discussion and assessment, historical calculator investigation, and a documentary worksheet.
Filename:
MLMF-Teaching-Pack-05-Student-Worksheets.pdf
Preparation, a 15-minute plan, read-aloud explanation, worked answers, assessment guidance, adaptations, and sources.
Filename:
MLMF-Teaching-Pack-05-Teacher-Guide.pdf
Print only what you need: Student pages 1 and 3 for the online core; pages 2 and 3 for the paper core. Pages 4–5 and the optional questions are extensions.
Continue the Learning
Purchasing Power Simulator · Inflation Calculator
Money vs. Currency · Teaching Pack 04 · Nominal Confusion
Hidden Secrets of Money, Episode 1 connects the activity to the documentary curriculum.
The U.S. Bureau of Labor Statistics CPI questions and answers explains what the CPI covers and why an average measure can differ from a particular household’s experience.
Return to Teaching Resources for the full collection. Prepared September 28, 2026.