Book cover for Intermediate Microeconomics: A Modern Approach

Intermediate Microeconomics: A Modern Approach

Hal R. Varian

ISBN #9780393927023

7th Edition

224 Questions

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Homework Questions

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Summary
Learning Objectives
Key Concepts
Example Problems
Explanations
Common Mistakes

Summary

This chapter on Equilibrium provides a comprehensive review of how markets achieve balance when supply equals demand, explores the roles of linear inverse demand and supply curves, and applies comparative statics to examine the impacts of external interventions such as taxes and subsidies. The section emphasizes understanding tax incidence, deadweight loss, and efficiency through Pareto Efficiency, with practical examples that link theory to everyday market scenarios.

Learning Objectives

1

Explain the concept of market equilibrium and the conditions under which it is achieved.

2

Analyze linear inverse demand and supply curves to determine equilibrium price and quantity.

3

Utilize comparative statics to evaluate how external factors like taxes and subsidies affect market outcomes.

4

Assess the impact of taxes on market performance, including tax incidence and deadweight loss.

5

Understand efficiency measures, specifically Pareto Efficiency, and their relevance in real-world market scenarios.

Key Concepts

CONCEPT

DEFINITION

Market Equilibrium

A state in a market where the quantity supplied equals the quantity demanded, indicating no inherent pressure for price or quantity to change.

Inverse Demand Curve

A function showing the relationship between the price of a good and the quantity demanded, expressed with price as the dependent variable.

Inverse Supply Curve

A function representing the relationship between the price of a good and the quantity supplied, with price written as a function of quantity.

Comparative Statics

An analytical method used to compare equilibrium states before and after a change in some external factor, such as government intervention or market shocks.

Tax Incidence

The manner in which the burden of a tax is distributed among buyers and sellers in the market.

Deadweight Loss

A loss of economic efficiency that occurs when the equilibrium outcome is not achieved due to market distortions like taxes or subsidies.

Pareto Efficiency

A state of resource allocation where it is impossible to make someone better off without making someone else worse off.

Example Problems

Example 1

What is the effect of a subsidy in a market with a horizontal supply curve? With a vertical supply curve?

Example 2

Suppose that the demand curve is vertical while the supply curve slopes upward. If a tax is imposed in this market who ends up paying it?

Example 3

Suppose that all consumers view red pencils and blue pencils as perfect substitutes. Suppose that the supply curve for red pencils is upward sloping. Let the price of red pencils and blue pencils be $p_{r}$ and $p_{b}$. What would happen if the government put a tax only on red pencils?

Example 4

4. The United States imports about half of its petroleum needs. Suppose that the rest of the oil producers are willing to supply as much oil as the United States wants at a constant price of $\$ 25$ a barrel. What would happen to the price of domestic oil if a tax of $\$ 5$ a barrel were placed on foreign oil?

Example 5

Suppose that the supply curve is vertical. What is the dead weight loss of a tax in this market?
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Step-by-Step Explanations

QUESTION

Given linear inverse demand (P = a - bQ) and supply (P = c + dQ) curves, how do you determine the market equilibrium?

STEP-BY-STEP ANSWER:

Step 1: Set the inverse demand equal to the inverse supply: a - bQ = c + dQ.
Step 2: Rearrange the equation to group the Q terms: a - c = bQ + dQ = Q(b + d).
Step 3: Solve for Q: Q = (a - c) / (b + d).
Step 4: Substitute Q back into either the demand or supply equation to calculate the equilibrium price, P.
Final Answer: The equilibrium price is obtained by P = a - b[(a - c)/(b + d)] and the equilibrum quantity by Q = (a - c)/(b + d).

Market Equilibrium Calculation

QUESTION

How does the imposition of a per-unit tax affect the market equilibrium and what are the resulting effects such as tax incidence and deadweight loss?

STEP-BY-STEP ANSWER:

Step 1: Recognize that a per-unit tax shifts either the supply or demand curve depending on which side of the market the tax is paid.
Step 2: Adjust the corresponding inverse function (e.g., if the tax is on suppliers, shift the supply curve upward by the tax amount).
Step 3: Set the adjusted supply curve equal to the original demand curve to determine the new equilibrium quantities.
Step 4: Calculate the new equilibrium price and note the difference between what buyers pay and what sellers receive to determine the tax incidence.
Step 5: Identify the reduction in traded quantity compared to the original equilibrium, and use it to calculate the deadweight loss, representing efficiency loss in the market.
Final Answer: The equilibrium shifts resulting in a higher price for buyers, a lower net price for sellers, and a deadweight loss from the reduced quantity traded.

Analyzing the Impact of a Tax

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Common Mistakes

  • Misinterpreting the difference between shifts in curves and movements along the curves.
  • Assuming that taxes have a uniform effect on buyers and sellers without considering tax incidence.
  • Overlooking the importance of calculating deadweight loss as a key efficiency measure.
  • Neglecting the comparative statics approach, which is crucial for understanding dynamic changes in market equilibrium.