Keynesian and Monetarist economics: How do they differ?

Monetarist economics is Milton Friedman's direct criticism of Keynesian economics theory, formulated by John Maynard Keynes. Simply put, the difference between these theories is that monetarist economics involves the control of money in the economy, while Keynesian economics involves government expenditures. Monetarists believe in controlling the supply of money that flows into the economy, while allowing the rest of the market to fix itself. In contrast, Keynesian economists believe that a troubled economy continues in a downward spiral unless an intervention drives consumers to buy more goods and services.

Both of these macroeconomic theories directly impact the way lawmakers create fiscal and monetary policies. If both types of economists were equated to motorists, monetarists would be most concerned with adding gasoline to their tanks, while Keynesians would be most concerned with keeping their motors running.

The terminology of demand-side economics is synonymous to Keynesian economics. Keynesian economists believe the economy is best controlled by manipulating the demand for goods and services. However, these economists do not completely disregard the role the money supply has in the economy and on affecting gross domestic product, or GDP. Yet, they do believe it takes a great amount of time for the economic market to adjust to any monetary influence.

Keynesian economists believe in consumption, government expenditures and net exports to change the state of the economy. Fans of this theory may also enjoy the New Keynesian economic theory, which expands upon this classical approach. The New Keynesian theory arrived in the 1980s and focuses on government intervention and the behavior of prices. Both theories are a reaction to depression economics.

Monetarists are certain the money supply is what controls the economy, as their name implies. They believe that controlling the supply of money directly influences inflation and that by fighting inflation with the supply of money, they can influence interest rates in the future. Imagine adding more money to the current economy and the effects it would have on business expectations and the production of goods. Now imagine taking money away from the economy. What happens to supply and demand?

Monetarist economics founder Milton Friedman believed monetary policy was so incredibly crucial to a healthy economy that he publicly blamed the Federal Reserve for causing the Great Depression. He implied it is up to the Federal Reserve to regulate the economy.

Presidents and other lawmakers have applied multiple economic theories throughout history. Soon after the Great Depression, President Herbert Hoover failed in his approach to balance the budget, which entailed increasing taxes and spending cuts. President Roosevelt followed next and focused his administration's efforts on increasing demand and lowering unemployment. It is worth noting that Roosevelt's New Deal and other policies increased the supply of money in the economy.

More recently, the 2007-08 financial crisis led President Obama and other lawmakers to address economic problems by bailing out banks and fixing underwater mortgages for government-owned housing. In these instances, it appears elements of Keynesian and Monetarist theories were used to reduce the national debt.