# How Do Fiscal and Monetary Policies Affect Aggregate Demand?

Aggregate demand (AD) is a macroeconomic concept representing the total demand for goods and services in an economy. This value is often used as a measure of economic well-being or growth. Both fiscal policy and monetary policy can impact aggregate demand because they can influence the factors used to calculate it: consumer spending on goods and services, investment spending on business capital goods, government spending on public goods and services, exports, and imports. It is often the cause of multiple trilemmas.

Fiscal policy affects aggregate demand through changes in government spending and taxation. Those factors influence employment and household income, which then impact consumer spending and investment.

Monetary policy impacts the money supply in an economy, which influences interest rates and the inflation rate. It also impacts business expansion, net exports, employment, the cost of debt, and the relative cost of consumption versus saving—all of which directly or indirectly impact aggregate demand.

### Key Takeaways

• Aggregate demand is an economic measure of the total demand for all finished goods or services created in an economy.
• It represents the overall demand regardless of the price level, during a specific period of time.
• Aggregate demand and gross domestic product (GDP) are calculated the same way and move in tandem, increasing or decreasing simultaneously.
• In the same way that fiscal and monetary policy impact GDP, they also impact aggregate demand.
• Fiscal policy impacts government spending and tax policy, while monetary policy influences the money supply, interest rates, and inflation.

## The Formula for Aggregate Demand

In order to understand how monetary and policy affect aggregate demand, it's important to know how AD is calculated, which is with the same formula for measuring an economy's gross domestic product (GDP):

\begin{aligned} &AD = C + I + G + (X - M)\\ &\textbf{where:}\\ &C=\text{Consumer spending on goods and services}\\ &I = \text{Investment spending on business capital goods}\\ &G = \text{Government spending on public goods and services}\\ &X = \text{Exports}\\ &M = \text{Imports}\\ \end{aligned}

## Understanding Fiscal Policy and Aggregate Demand

Fiscal policy determines government spending and tax rates. Expansionary fiscal policy, usually enacted in response to recessions or employment shocks, increases government spending in areas such as infrastructure, education, and unemployment benefits.

According to Keynesian economics, these programs can prevent a negative shift in aggregate demand by stabilizing employment among government employees and people involved with stimulated industries. The theory is that extended unemployment benefits help to stabilize the consumption and investment of individuals who become unemployed during a recession.

Similarly, the theory says that contractionary fiscal policy can be used to reduce government spending and sovereign debt or to correct out-of-control growth fueled by rapid inflation and asset bubbles.

In relation to the formula for aggregate demand, the fiscal policy directly influences the government expenditure element and indirectly impacts the consumption and investment elements.

Fiscal and Monetary Policy Impact on GDP

## Understanding Monetary Policy and Aggregate Demand

Monetary policy is enacted by central banks by manipulating the money supply in an economy. The money supply influences interest rates and inflation, both of which are major determinants of employment, cost of debt, and consumption levels.

Expansionary monetary policy involves a central bank buying Treasury notes, decreasing interest rates on loans to banks, or reducing the reserve requirement. All of these actions increase the money supply and lead to lower interest rates.

This creates incentives for banks to loan and businesses to borrow. Debt-funded business expansion can positively affect consumer spending and investment through employment, thereby increasing aggregate demand.

Expansionary monetary policy also typically makes consumption more attractive relative to savings. Exporters benefit from inflation as their products become relatively cheaper for consumers in other economies.

Contractionary monetary policy is enacted to halt exceptionally high inflation rates or normalize the effects of expansionary policy. Tightening the money supply discourages business expansion and consumer spending and negatively impacts exporters, which can reduce aggregate demand.

Monetary policy involves tools employed by a monetary authority (like a central bank), such as changing interest rates or reserve requirements. Fiscal policy involves tools used by a government, such as taxation or federal spending.

## How Does Monetary Policy Increase Aggregate Demand?

Monetary policy is thought to increase aggregate demand through expansionary tools. These include lowering interest rates and engaging in open market operations (OMO) to purchase securities. These have the effect of making it easier and cheaper to borrow money, with the hope of incentivizing spending and investment.

## What Fiscal Policy Increases Aggregate Demand?

Expansionary fiscal policy that is intended to increase aggregate demand includes cutting taxes and increasing government spending. Both provide more money to consumers and businesses, allowing them to purchase and invest.

## What Is Aggregate Supply?

Aggregate supply can be thought of as the yin to aggregate demand's yang. In Keynesian economics, aggregate supply is the total output of an economy. In theory, there is equilibrium when aggregate supply matches the level of aggregate demand.