A return means little until rising prices are taken off it.
Count in real money.
Four savings offers, for one year. Tap the best.
The biggest rate lost the most. Count what your money gets you, not the number.
← Red LinesRed Line 10 of 48 The idea The numbers Where you see it Where it bends This game’s numbersHow strong the proof is Where it comes from
A return in euros counts the euros. What matters is what they buy. Take rising prices off first, then judge.
€10,000 earning 2% a year is about €12,200 after 10 years. With prices up 3% a year, it buys what about €9,100 buys today: less than you started with.
Over two centuries of US data, shares returned about 6.7% a year after inflation. Serious long-run figures are quoted after inflation for this reason.
When prices fall, cash quietly gains.
ECB Data Portal: euro area HICP, annual average rateEurostat: HICP annual average (prc_hicp_aind)Worked out on this page
=Outside the four steps: it follows from the arithmetic
True by the sumsWhat a return buys is the return minus the rise in prices. That follows from the sums, as Fisher set out.
- The Theory of Interest Irving Fisher, Macmillan, 1930
Checked 2 Nov 2026 · How we grade
- A Strong proof: Many good studies or long official data, from different teams or countries, point the same way.
- B Good proof, with limits: Solid studies agree on the direction, but the size varies, or the data covers few places or few kinds of people.
- C Mixed proof: Some good studies for, some against, or the evidence covers only part of the line.
- D Thin proof: Mostly one book’s argument, one survey or stories. It may be wise, but it has not been tested well.
- = True by the sums: It follows from arithmetic, so no study can overturn it. We still show what real data says.
Jeremy J. Siegel, Stocks for the Long Run (1994). In our words, not quoted.
See it in numbers: Real rate · Inflation (From Zero)
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