Higher prices sound bad for everyone. But prices are also incomes: the price of labor is a wage. Using Converting Nominal to Real, we can see who really loses from inflation, and when.
Key idea
Unexpected inflation moves buying power from lenders to borrowers and hurts people whose incomes or savings are fixed in dollars. All inflation brings costs such as menu costs (changing posted prices), shoe-leather costs (effort spent holding less cash) and confusion about values over time.
Why it works
A loan is a promise to repay a fixed number of dollars. If prices rise faster than both sides expected when they agreed on the interest rate, the dollars repaid buy less than planned: the borrower gains and the lender loses. If inflation is expected, the lender builds it into the interest rate, so neither side is surprised. Meanwhile, when wages rise along with prices, workers' buying power does not fall: real income depends on wages compared with prices, not on prices alone.
Worked examples
Worked example: A loan and a surprise
A bank lends at 7%, expecting 3% inflation. Inflation turns out to be 6%. What real return did the bank expect, and what did it get?
- Expected real rate $\approx 7\% - 3\% = 4\%$.
- Actual real rate $\approx 7\% - 6\% = 1\%$.
- The surprise moved about 3 percentage points of real return from the bank to the borrower.
Answer: Expected 4%, got 1%
Worked example: Wages and prices together
Prices rise 5% this year, and wages also rise 5%. What happens to workers' buying power?
- Real wage growth $\approx 5\% - 5\% = 0\%$.
- Buying power is unchanged. Inflation hurts workers when wages lag behind prices, not by itself.
Answer: No change
Some incomes are protected by indexing: U.S. Social Security benefits are raised each year with a price index. Other costs remain: firms spend effort changing prices, people hold less cash, and when the value of a dollar keeps shifting, it is harder to compare prices and profits over time and to plan.
Common mistake
Thinking inflation makes everyone poorer by the inflation rate. When wages rise along with prices, real income need not fall, and surprise inflation helps borrowers while it hurts lenders. Check: compare the growth of each person's income (or the interest they pay or earn) with the inflation rate.