Keynesian Economics Theory

How it works with examples

keynesian economics vs. classic economics

The Balance / Lara Antal

Keynesian economics is a theory that says the government should increase demand to boost growth. Keynesians believe that consumer demand is the primary driving force in an economy. As a result, the theory supports the expansionary fiscal policy. Its main tools are government spending on infrastructure, unemployment benefits, and education. A drawback is that overdoing Keynesian policies increases inflation.

The British economist John Maynard Keynes developed this theory in the 1930s. The Great Depression had defied all prior attempts to end it. President Franklin D. Roosevelt used Keynesian economics to build his famous New Deal program. In his first 100 days in office, FDR increased the debt by $3 billion to create 15 new agencies and laws. For example, the Works Progress Administration put 8.5 million people to work. The Civil Works Administration created four million new construction jobs.

Keynes described his premise in “The General Theory of Employment, Interest, and Money.” Published in February 1936, it was revolutionary. First, it argued that government spending was a critical factor driving aggregate demand. That meant an increase in spending would increase demand. Second, Keynes argued that government spending was necessary to maintain full employment.

Keynes advocated deficit spending during the contractionary phase of the business cycle. In recent years, politicians have used it even during the expansionary phase. President Bush's deficit spending in 2006 and 2007 increased the debt. It also helped create a boom that led to the 2007 financial crisis. President Trump increased debt during stable economic growth. That will also lead to a boom-and-bust cycle.

Keynesian Economics
  • Government spending on infrastructure, unemployment benefits, and education will increase consumer demand.

  • Government spending is necessary to maintain full employment.

Classical Economics
  • Increasing business growth will boost the economy.

  • Government should play a limited role and target companies, not consumers.

Keynesian Versus Classical Economic Theories

The classical economic theory promotes laissez-faire policy. It says the free market allows the laws of supply and demand to self-regulate the business cycle. It argues that unfettered capitalism will create a productive market on its own. It will enable private entities to own the factors of production. These four factors are entrepreneurship, capital goods, natural resources, and labor. In this theory, business owners use the most efficient practices to maximize profit.

Classical economic theory also advocates for a limited government. It should have a balanced budget and incur little debt. Government spending is dangerous because it crowds out private investment, but that only happens when the economy is not in a recession. In that case, government borrowing will compete with corporate bonds. The result is higher interest rates, which make borrowing more expensive. If deficit spending only occurs during a recession, it will not raise interest rates. For that reason, it also won't crowd out private investment.


Supply-side economists say that increasing business growth, not consumer demand, will boost the economy. They agree the government has a role to play, but fiscal policy should target companies. They rely on tax cuts and deregulation.

Proponents of trickle-down economics say that all fiscal policy should benefit the wealthy. Since the wealthy are business owners, benefits to them will trickle down to everyone.

Monetarists claim that monetary policy is the real driver of the business cycle. Monetarists like Milton Friedman blame the Depression on high-interest rates. They believe the expansion of the money supply will end recessions and boost growth.

Socialists criticize Keynesianism because it doesn't go far enough. They believe the government should take a more active role to protect the common welfare. This role means owning some factors of production. Most socialist governments own the nation's energy, health care, and education services.

Even more critical are communists. They believe the people, as represented by the government, should own everything. The government completely controls the economy.

Keynesian Multiplier

The Keynesian multiplier represents how much demand each dollar of government spending generates. For example, a multiplier of two creates two dollars of gross domestic product (GDP) for every dollar of spending. Most economists agree that the Keynesian multiplier is one. Every dollar, the government spends adds a dollar to economic growth. Since government spending is a component of GDP, it has to have at least this much impact.


The Keynesian multiplier also applies to decreases in spending. The International Monetary Fund estimated that a cut in government spending during a contraction has a multiplier of 1.5 or more. Governments who insist on austerity measures during a recession remove $1.50 from GDP for every dollar cut.

New Keynesian Theory

In the 1970s, rational expectations theorists argued against the Keynesian theory. They said that taxpayers would anticipate the debt caused by deficit spending. Consumers would save today to pay off future debt. Deficit spending would spur savings, not increase demand or economic growth. 

The rational expectations theory inspired the New Keynesians. They said that monetary policy is more potent than fiscal policy. If done right, expansionary monetary policy would negate the need for deficit spending. Central banks don't need politicians’ help to manage the economy. They would merely adjust the money supply.


President Roosevelt tried to ease the effects of the Great Depression by spending on job creation programs. He created Social Security, the U.S. minimum wage, and child labor laws, as well as the Federal Deposit Insurance Corporation, which prevents bank runs by insuring deposits.

President Ronald Reagan promised to reduce government spending and taxes. He called these traditional Republican policies, Reaganomics. He cut income taxes and the corporate tax rate. Instead of reducing the debt, Reagan more than doubled it, but that helped end the 1981 recession.

Bill Clinton's expansionary economic policies fostered a decade of prosperity. He created more jobs than any other president. Homeownership was 67.7%, the highest rate ever recorded. The poverty rate dropped to 11.8%.

Barack Obama's policies ended the Great Recession with the Economic Stimulus Act. This act spent $224 billion in extended unemployment benefits, education, and health care. It created jobs by allocating $275 billion in federal contracts, grants, and loans. It cut taxes by $288 billion. Obamacare slowed the growth of health care costs.

Frequently Asked Questions (FAQs)

What distinguishes Keynesian economic theory from supply-side economics?

Keynesian economic theory is essentially the opposite of supply-side economics, which emphasizes business growth and deregulation. Keynesian economics promotes government intervention to promote consumer demand.

What is the Keynesian solution for inflation?

Keynesian economists promote raising taxes to cool down the economy during inflationary periods. However, this strategy doesn't work as well during periods of "stagflation," when inflation is paired with an already sluggish economy.

Was this page helpful?
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.
  1. International Monetary Fund. "What Is Keynesian Economics?"

  2. Franklin D. Roosevelt Library & Museum. "FDR: From Budget Balancer to Keynesian."

  3. Treasury Direct. "Historical Debt Outstanding - Annual 1900 - 1949."

  4. Yonkers Public Schools. "Roosevelt and the New Deal - The First Hundred Days," Page 652.

  5. U.S. Library of Congress. "Works Progress Administration."

  6. U.S. National Archives and Records Administration. "Family Experiences and New Deal Relief."

  7. Center on Budget and Policy Priorities. "Getting the Facts Straight."

  8. Council on Foreign Relations. "The U.S. Financial Crisis - February 2007 U.S. Housing Bubble Bursts."

  9. Council on Foreign Relations. "The National Debt Dilemma."

  10. History & Policy. "Crowding Out."

  11. The Library of Economics and Liberty. "Supply-Side Economics."

  12. The Wharton School. "Does Trickle-Down Economics Add Up – Or Is It a Drop in the Bucket?"

  13. International Monetary Fund. "What Is Monetarism?"

  14. Socialist Party. "Socialism vs Capitalism."

  15. Communism and Computer Ethics. "History and Background of Communism."

  16. Federal Reserve Bank of Minneapolis. "Rational Expectations—Fresh Ideas that Challenge Some Established Views of Policy Making."

  17. The Library of Economics and Liberty. "New Keynesian Economics."

  18. University of Virginia Miller Center. "Franklin D. Roosevelt - Key Events."

  19. TreasuryDirect. "The New Deal (1933-1936) to World War II (1939-1945)."

  20. Northeastern University Economics Society. "Political Economics in Brief: 'Reaganomics'."

  21. Clinton White House. "Bringing Homeownership Rates to Historic Levels."

  22. Clinton White House. "The Clinton Presidency: Historic Economic Growth."

  23. Neva Goodwin, Jonathan Harris, Julie Nelson, et al. "Principles of Economics in Context," Page 576. M.E. Sharpe, 2014.

Related Articles