Question

On a microeconomic demand curve, a decrease in price causes an increase in quantity demanded because the product in question is now relatively less expensive than substitute products. Explain why aggregate demand does not increase for the same reason in response to a decrease in the aggregate price level. In other words, what causes total spending to increase if it is not because goods are now cheaper?

Short answer

In conclusion, aggregate demand does not increase like the microeconomic demand curve in response to a decrease in the aggregate price level. This is because the aggregate price level affects all goods and services, making substitution between individual goods irrelevant. Instead, factors like changes in expectations, the wealth effect, and substitution with other financial options (such as savings or investments) might offset the potential increase in aggregate demand due to lower aggregate prices.

Step-by-step solution

Understand the microeconomic demand curve

In microeconomics, we deal with the demand curve for an individual product or service. The demand curve represents the relationship between the quantity demanded and the price level. As the price of a product decreases, consumers are more likely to purchase the product due to its increased affordability and the fact that it is a more appealing option compared to substitutes. This causes the quantity demanded to increase as consumers substitute the more affordable product with other goods.

Understand the aggregate demand curve

Aggregate demand is the total demand for all goods and services in an economy. Unlike microeconomic demand, aggregate demand looks at the overall price level in the economy, which includes all goods and services. The aggregate demand curve shows the relationship between the overall price level and the total spending in the economy.

Discuss the role of expectations and the wealth effect

In the macroeconomic context, a decrease in aggregate price level doesn't necessarily increase aggregate demand because it doesn't lead to a substitution between individual goods. This is because the aggregate price level is a broad measure that affects all goods and services. Additionally, a decrease in the aggregate price level may lead to changes in expectations and the wealth effect. - Expectations: If consumers expect prices to continue decreasing, they may postpone their consumption, leading to a decline in aggregate demand. - Wealth effect: A decrease in the overall price level may lead households to feel that their real wealth has increased (since their money can now buy more goods), initially increasing aggregate demand. However, this effect is often outweighed by other factors, which bring us to the final step.

Identify the difference in substitution effects

In the aggregate demand context, a decrease in price level might prompt people to substitute goods and services not with other goods but with other financial options, such as savings. If aggregate prices fall, consumers might save more or invest their money in financial assets (stocks, bonds, etc.), instead of consuming more goods and services. This action can offset the potential increase on aggregate demand due to the decrease of the aggregate price level. In conclusion, aggregate demand does not increase like the microeconomic demand curve in response to a decrease in the aggregate price level due to the overall impact on all goods and services, changes in expectations and the wealth effect, and the difference in substitution effects. Instead of substituting goods with one another, consumers might substitute their spending with other financial options like savings or investments.