Causes of the Business Cycle

Three Ways Monetary and Fiscal Policy Change It

Monopoly game board representing the business cycle.

Christopher Furlong / Getty Images

The business cycle is caused by the forces of supply and demand—the movement of the gross domestic product GDP—the availability of capital, and expectations about the future. This cycle is generally separated into four distinct segments: expansion, peak, contraction, and trough. You may hear this series referred to as the "economic" or "trade" cycle.

Here's what causes each of the four phases of the boom and bust cycle.

Business Cycle Expansion Phase

When consumers are confident, they buy now. They know there will be future income from better jobs, higher home values, and increasing stock prices. As demand increases, businesses hire new workers. The increase in consumer income further stimulates demand. A little healthy inflation can trigger demand by spurring shoppers to buy now before prices go up. 

A healthy expansion can suddenly turn into a dangerous peak. It happens when there's too much money chasing too few goods. It can cause either price inflation or an asset bubble.

Peak Phase

If demand outstrips supply, then the economy can overheat. Investors and businesses compete to outperform the market, taking on more risk to gain some extra return. This combination of excess demand and the creation of risky derivatives created the housing bubble in 2005.

You can always recognize a peak by two things: First, the media says that the expansion will never end. Second, it seems that everyone and their brother are making tons of money from whatever the asset bubble is.

Business Cycle Contraction Phase

A contraction causes a recession. Three types of events trigger a contraction. They are a rapid increase in interest rates, a financial crisis, or runaway inflation. Fear and panic replace confidence. Investors sell stocks and buy bonds, gold, and the U.S. dollar. Consumers lose their jobs, sell their homes, and stop buying anything but necessities. Businesses lay off workers and hoard cash. 

Trough Phase

Consumers must regain confidence before the economy can enter a new expansion phase. That often requires intervention with monetary or fiscal policy. In an ideal world, they work together, but unfortunately, that doesn't occur often enough.

How Monetary Policy Changes the Business Cycle

Monetary policy is how the nation's central bank manages the economic cycle. It adjusts liquidity by changing interest rates and the money supply.

Expansion: Central banks try to keep the core inflation rate around 2% to create a healthy expectation of inflation. In the United States, the Federal Reserve will keep the fed funds rate right around 2%. If economic growth remains at a healthy growth rate, the Fed won't make any changes.

Peak: Central banks raise interest rates during expansion to avoid the irrational exuberance of a peak. That is called "contractionary monetary policy." If needed, they will sell Treasury bonds and other assets during open market operations.

Contraction: At this point, a stock market correction may indicate that assets are overvalued. The Fed can switch to expansionary monetary policy if economic growth slows or even turns negative. It will lower interest rates and buy Treasurys in open market operations.

Trough: Central banks pull out all the tools to jump-start the economy out of a trough. In 2008, the Fed used a variety of innovative tools to keeps banks from collapsing. It also expanded its open market operations in a program called "quantitative easing."

How Fiscal Policy Changes the Business Cycle

Fiscal policy is what elected officials use to change the business cycle, but they disagree on the best ways to implement it. As a result, they don't take advantage of the power of fiscal policy.

Expansion: When the economy is in the expansion phase, politicians are content because their constituents are happy. They will pursue other policies, such as foreign affairs, defense, or immigration.

Peak: During the irrational exuberance phase, politicians continue to ignore fiscal policy. They would be smart to pursue a contractionary fiscal policy to avoid the peak. But politicians don't get re-elected when they either raise taxes or cut spending.

Contraction: This is when expansionary fiscal policy is crucial. Elected officials are quick to cut taxes and increase spending to create jobs, demand, and confidence. The best unemployment solution in a contraction is government spending on public works and education jobs.

Trough: By this point, there is so much outcry among voters that the elected officials must do something to turn things around. That was successfully done in 2009 with the American Recovery and Reinvestment Act, which led to the end of the Great Recession.

Frequently Asked Questions (FAQs)

Which part of the business cycle causes an increase in inflation?

Inflation tends to increase during the expansion phase of the business cycle. However, these tendencies don't always play out in the real world. From 2009 to 2020, the economy expanded while inflation remained low. When inflation rises during a contraction, that's known as "stagflation."

Why is it difficult to explain the causes of the business cycle?

Perfectly identifying the cause of an economic trend is difficult, because economies are large and complicated. The U.S. economy includes roughly 164 million workers creating more than $24 trillion worth of domestic product.

Small instances of supply and demand collectively add up to this massive economy, but each person's demand doesn't usually show a measurable impact on economic indicators. Some single actions are large enough to show an impact, such as when a government directs trillions of dollars toward a single monetary or fiscal goal.

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The Balance uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
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  2. Center for American Progress. "The 2008 Housing Crisis."

  3. Federal Reserve Bank of St. Louis. "What Is a Recession?"

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  11. Federal Reserve Bank of St. Louis. "Gross Domestic Product (GDP)."

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