Inflation & Purchasing Power
Separate the future nominal cost of the same basket from the future of a fixed nominal amount.
Question, try, then observe
What will 10,000 buy in ten years?
Change inflation and time to compare fixed-money purchasing power with future living costs.
Hypothetical teaching scenario; results update immediately.
Constant annual inflation; excludes interest, tax and investment returns.
What did you just see?
With positive inflation, the same basket costs more and a fixed amount buys less. Deflation reverses both directions.
The cumulative effect of time
The chart holds nominal money fixed and excludes interest, taxes and investment returns. Fractional years use the equivalent power of the fixed annual rate, not an observed monthly price path.
Another example
- Set 10,000 USD, 3% and ten years.
- The factor is 1.03^10; cumulative inflation is about 34.3916%.
- Multiply for future cost and divide for purchasing power in today’s money.
Show formal definition and formula
Constant annual inflation compounds into a price growth factor. Multiply today’s basket cost by this factor for its future nominal cost; divide a fixed nominal amount by the same factor for future purchasing power in today’s money.
Future cost of the same basket
Future purchasing power of a fixed amount
Cumulative price change
Constant annual inflation compounds into a price growth factor. Multiply today’s basket cost by this factor for its future nominal cost; divide a fixed nominal amount by the same factor for future purchasing power in today’s money.
- A
- Today's basket cost or a fixed nominal amount (TWD)
- π
- Constant annual inflation rate
- t
- Elapsed years
- F
- Future nominal cost of the same basket (TWD)
- P
- Purchasing power of fixed nominal money, in today's TWD
- c
- Cumulative price change over the full period
- Units
- π and c are decimal rates: 3% = 0.03; displays use percentages. t is in years, amounts in TWD; P uses today's prices and F future nominal prices.
Common mistakes
Do not confuse future basket cost with fixed-money purchasing power. Constant inflation is a model assumption, not a forecast. The representative CPI basket differs from each person’s spending mix.
Frequently asked questions
What about zero inflation or zero years?
The factor is one, both amounts equal the input, and cumulative inflation is zero.
You can now explore…
- Separate future costs from fixed-money purchasing power
- Explore inflation and time cumulatively
Term reference1 terms
Open a term when you need a reminder. Underlined words in the article work too.