nominal vs real values
Imagine your salary rose 5 percent this year and you feel richer — until you notice prices also rose 5 percent, so you can buy exactly the same as before. The number on your payslip went up (good!), but what it actually buys did not budge. This gap between the dollar figure and what that figure can purchase is the difference between nominal and real values, and missing it is one of the most common money mistakes there is.
A nominal value is measured in current money, at the prices of the time — the face number. A real value strips out inflation to show purchasing power, measured in the prices of a fixed base year, so different years can be compared fairly. The rough rule for rates: real change is approximately nominal change minus inflation. A 5 percent raise with 5 percent inflation is a 0 percent real raise. For levels, you deflate by a price index: real value = nominal value divided by (price index / 100).
Distinguishing nominal from real is the cure for "money illusion" — being fooled by the bigger number. It is everywhere: real GDP versus nominal GDP, real wages, real interest rates, real returns on investments. A historical wage of 1 dollar an hour was not necessarily poverty if prices were tiny then; only the real wage tells you. The honest caveat: converting nominal to real depends on which price index you pick, and no single index perfectly captures everyone's cost of living, so real figures are good comparisons, not exact truths.
Your pay rises from 50,000 to 52,500 dollars, a 5 percent nominal raise. But prices also rose 5 percent. In real terms your pay is unchanged — 52,500 / 1.05 = 50,000 in last year's money. The number grew; your buying power did not.
A bigger paycheck means nothing if prices rose just as fast.
Mistaking nominal for real is "money illusion." To compare across years honestly, always adjust money figures for inflation — but remember the choice of price index colours the result.