3.21
The multiplier is a macroeconomic concept that explains how a small change in spending or investment can lead to a larger change in total output.
For example, a businessman invests twenty-five thousand dollars in new equipment. The manufacturer uses this money to pay for raw materials, wages, and logistics. Those who receive this income spend it on other goods and services, creating a ripple effect through the economy.
Before this, the businessman had one hundred twenty-five thousand dollars invested in his business. On the aggregate expenditure graph, this is shown as AE = 125. The economy starts in equilibrium at point A, where AE = 125 intersects the 45-degree line, and output is five hundred thousand dollars.
With the new investment, the AE curve shifts upward to AE = 150. At point A, spending now exceeds output, so firms increase production. A new equilibrium is reached at point B, where output is six hundred thousand dollars.
The output rises by one hundred thousand dollars. Dividing this change in output by the new investment of twenty-five thousand dollars gives a multiplier of four.
The multiplier is an idea that helps explain how a small change in spending can lead to a much bigger change in the total income of an economy. It wor…
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