Nominal Value vs Real Value
Nominal Value and Real Value are two Economic Indicators & Data concepts in AP Economics that students often mix up. Nominal values are measured in the prices of the period when they occurred, so they mix changes in quantity together with changes in prices. Real values are nominal figures adjusted for price changes, so they are stated in the prices of one base year and reflect quantities rather than inflation. Here is how they compare side by side.
A nominal figure is what a transaction was worth in the money of its own time, with no correction for inflation, which is why nominal wages, nominal GDP and nominal interest rates all overstate real gains when prices are rising. Nominal GDP can grow in a year when the country produced less, if prices rose faster than output fell. Nominal values are not wrong; they are the actual amounts paid, and they are the correct measure for anything settled in current money, such as a loan payment or a tax bill. Trouble starts when nominal figures from different periods get compared directly, because part of the difference is nothing but the change in the price level. Dividing by a price index converts them to real terms and makes the comparison meaningful.
Converting a nominal figure to real terms means dividing it by a price index written as a decimal, a step called deflating. What survives is the part of the change that came from producing or buying more, with the price effect stripped out, so real GDP growth measures output and real wage growth measures purchasing power. Every real series is quoted in the prices of a particular base year, which is why a phrase like in base-year dollars follows the number. Because the deflator is itself an estimate, real figures carry more measurement uncertainty than nominal ones and get revised whenever price indexes are revised. Comparing output, wages or living standards across years is the situation where nominal numbers give the wrong answer and real numbers give the right one.
Nominal vs Real Value: Taking Inflation Back Out of a Number
| Nominal Value | Real Value | |
|---|---|---|
| Prices used | The prices of the period when it happened | The prices of one chosen base year |
| What a rise tells you | Quantities and prices moving together, mixed | Quantities only |
| Effect of inflation on the series | Inflation alone can make it rise | Inflation is stripped out, so it can fall while the nominal series rises |
| How you get it | Read straight off the transaction or the account | Divide the nominal figure by a price index and multiply by 100 |
| What it is good for | Comparing amounts inside a single period | Comparing output or living standards across years |
| Examples | Nominal GDP, a posted wage, a quoted interest rate | Real GDP, a real wage, a real interest rate |
The whole operation is one division, and the deflator does the work
To move from nominal to real you divide by a price index and multiply by 100, and that is the entire procedure. Work an illustrative case. Nominal GDP is 22,000 billion and the GDP deflator stands at 110, with the base year set to 100. Real GDP is 22,000 divided by 110 times 100, which is 20,000 billion. A year later nominal GDP is 23,100 billion, a rise of 5 percent, and the deflator is 115.5. Real GDP is 23,100 divided by 115.5 times 100, which is 20,000 billion again. Nominal output rose 5 percent and real output did not move at all, because the whole increase was price. That is why headlines quoting a nominal figure tell you almost nothing about whether an economy produced more. Two habits follow. First, always ask which prices a figure is stated in before comparing it with another year. Second, remember that in the base year the two figures are equal by construction, because the index equals 100 there, so the real series sits exactly on top of the nominal one at that single point. The division is worked step by step at /calculate/real-gdp.
The same adjustment settles arguments about wages and interest
The distinction earns its keep outside national accounts. Take an illustrative pay rise. An hourly wage goes from 20 to 21, a rise of 5 percent, while the consumer price index goes from 100 to 108. The real wage in base year prices is 21 divided by 1.08, which is about 19.44, down from 20, so purchasing power fell by roughly 2.8 percent even though the paycheck grew. Anyone arguing about whether workers are better off is arguing about that second number, whether or not they say so. Interest works the same way. If a savings account pays 6 percent while prices rise 4 percent, the real return is close to 2 percent, since the approximation subtracts inflation from the nominal rate. Lend at 3 percent into 5 percent inflation and the real return is negative, meaning the money returned buys less than the money lent. The lesson carries to any figure quoted across time: a minimum wage, a tuition bill, a government deficit, a house price. If the years being compared had different price levels, the nominal comparison is measuring the currency as much as the thing. See /glossary/real-interest-rate for the lending case.
Frequently asked questions
What is the difference between nominal and real value?
A nominal value is measured in the prices of the period in which it occurred, while a real value is the same figure restated in the prices of a single base year so that inflation is removed. Nominal changes mix quantity and price together, and real changes show quantity alone.
How do you convert a nominal value into a real one?
Divide the nominal figure by the relevant price index for that period and multiply by 100. Use the GDP deflator for output, and a consumer price index for wages, incomes and household spending, and state clearly which base year the result is expressed in.
Can real GDP fall while nominal GDP rises?
Yes, and that combination is common in a year with high inflation. If the price level rises faster than nominal output does, the nominal figure still grows while the quantity of goods and services actually produced shrinks, which is exactly the situation the real measure exists to reveal.
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