What Is Inflation?

Definition & Examples of Inflation

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Inflation refers to a general increase in the prices of goods and services in the economy over time that corresponds with a decrease in the value of money.

Learn how inflation works and affects consumers, savers, and investors, how it's measured, and how to distinguish it from deflation.

What Is Inflation?

The simple definition of inflation is the sustained upward movement in the overall price level of goods and services in the economy. It has the effect of devaluing a particular currency. When a unit of currency depreciates in value, so does purchasing power, as it takes more currency units to buy the same amount of goods and services than it did in the past. In other words, your money buys you less stuff, be it bread, toothpaste, rent, or medical check-ups. 

How Inflation Works

Many consumers erroneously associate inflation with the rise in the price of a few key goods or services, such as oil, or even a particular industry, such as real estate. But inflation is by definition only present when the overall price of goods and services is rising. Two main forces are thought to be responsible for this increase in the economy-wide prices of goods and services: demand-pull inflation and cost-push inflation.

With demand-pull inflation, the demand for goods and services in the economy exceeds the economy's ability to produce them, and their short supply places upward pressure on prices and gives rise to inflation.

Cost-push inflation is a phenomenon wherein the rising price of input goods and services increases the price of final goods and services and causes inflation. For example, an oil crisis often causes a decrease in the oil supply and an increase in the price of petroleum, an important input good. The rising price of petroleum puts upward pressure on the price of final goods and services, leading to a temporary increase in inflation.

Inflation affects individuals and the economy. When inflation rises faster than wages increase, it causes a decrease in purchasing power that forces individuals to fork over more dollars, euros, or other forms of currency to buy necessities ranging from food and clothing to medical services, which can put the average consumer in a financial pinch and reduce discretionary spending. For example, as a result of inflation, you would have to pay $101 in 2020 to buy what could have been bought for $100 in 2019. It can also hurt savers, as inflation diminishes the value of the interest you earn on your deposits.

Some investors may also lose as a result of inflation. The central bank of a government will often adjust short-term interest rates to maintain the desired rate of inflation. For example, amidst rising inflation, the Federal Reserve often raises a short-term interest rate known as the federal funds rate, which typically results in a decrease in the value of fixed-rate securities such as fixed-rate bonds. This can hurt retirees who depend on a fixed income from such investments.

However, inflation isn't always a bad thing. If you invest in securities that offer protection against inflation—Treasury Inflation-Protected Securities (TIPS), for example—you may even see the value of your investment go up during an inflationary period. Similarly, borrowers may stand to gain from inflation if it corresponds with increasing wages, as they will get to repay debts with money that is worth less than it was before. If inflation doesn't correspond with wage increases, lenders may benefit from inflation at the expense of borrowers, as consumers may have a stronger motivation to borrow to afford the things they need. Lenders may further benefit from raising interest rates to guard against future inflation.

A rise in the price of a single good or service isn't considered inflation. Inflation only occurs with a general increase in the price level of goods and services throughout the economy.

How to Measure Inflation

The inflation rate is typically measured by changes in something called a price index. The most popular price index in the United States is the Consumer Price Index (CPI), which is a measure of the average change over time in the price of a standard set of consumer goods and services known as a market basket. CPI is calculated by dividing the price of a market basket in a particular year with the price of the basket in the base year. Find the rate of inflation by calculating the percentage change in the CPI from one point in time to another. For example, the Consumer Price Index for All Urban Consumers (CPI-U) was 256.57 in July 2019 and 259.10 in July 2020, resulting in an inflation rate of about 1% over the year.

Inflation vs. Deflation

Inflation Deflation
Marked by a general increase in the prices of goods and services Marked by a general decrease in the prices of goods and services
Caused by demand-pull or cost-push inflation Caused by contractions in the economy or the supply of money or credit
Decreases purchasing power Increases purchasing power

Whereas inflation is associated with a general increase in the price of goods and services and a decrease in the value of money, deflation refers to a general decrease in the price of goods and services and an increase in the value of money. If the percent change between CPI from one period to another is negative, you have deflation; the reverse is true for inflation.

A negative rate of inflation indicates deflation.

Unlike inflation, which is typically caused by demand-pull or cost-push inflation, deflation is typically caused by contractions in the economy or the supply of money or credit. As a consequence, consumers may buy more with a unit of currency, whereas inflation generally forces people to buy less if their wages have not kept up with inflation.

But deflation can have a similarly negative impact on consumers and the economy as inflation. For example, it's often associated with less demand for goods and services, which can force firms to take cost-cutting measures that can increase the unemployment rate.

Key Takeaways

  • Inflation is a general increase in the price level of goods and services in the economy over time.
  • It's caused by demand-pull or cost-push inflation.
  • It can hurt everyday consumers, savers, and fixed-income investors, but it can help inflation-protected investors as well as borrowers and lenders in certain circumstances.
  • Inflation is the opposite of deflation, which is marked by a general decrease in the prices of goods and services.

Article Sources

  1. Congressional Research Service. "Introduction to U.S. Economy: Inflation," Page 1. Accessed Aug. 17, 2020.

  2. BLS. "CPI Inflation Calculator." Accessed Aug. 17, 2020.

  3. BLS. "Consumer Price Index – July 2020," Page 4. Accessed Aug. 17, 2020.

  4. BLS. "Consumer Price Index – July 2019," Page 4. Accessed Aug. 17, 2020.

  5. FDIC. "An Update on Emerging Issues in Banking," Page 1. Accessed Aug. 17, 2020.