Wize University Microeconomics Textbook > Monopolistic Competition

Short Run vs Long Run Equilibrium

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Short and Long Run Equilibrium

In the short run a firm in monopolistic competition can make a profit or a loss, but in the long run they will make zero profit.

Short Run with Economic Profit

Image illustrating Short and Long Run Equilibrium


  • In the short run the business will maximize its profit where Marginal Revenue (MR) = Marginal Cost (MC). In the diagram above, this would occur at an output of ________.
  • Plug this quantity in the demand to get the price which would be ________
  • Plug this quantity in the ATC which would be ________
  • Calculate the profit using the formula Profit = (P - ATC) * Q = ________
  • Since the business is making a profit, other firms will ________ the industry in the long run and this will cause the demand for the existing firms to shift to the ________.

Long Run


Image illustrating Short and Long Run Equilibrium


  • In the long run the demand will keep shifting left until it is just touching (tangent to) the ATC curve and MR = MC still.
  • The output in the long run would be ________ units
  • Plug this quantity in demand to get the price which would be ________
  • Plug this quantity in ATC which would be ________
  • Profit = ________. In the long run every firm is making 0 profit in monopolistic competition.

Short Run with Economic Loss

Image illustrating Short and Long Run Equilibrium


  • In the short run we still make MR = MC. In the diagram above, this would occur at an output of ________.
  • Plug this quantity in the demand to get the price which would be ________
  • Plug this quantity in the ATC which would be ________
  • Calculate the profit using the formula Profit = (P - ATC) * Q = ________
  • Since the business is making a loss, other firms will ________ the industry in the long run and this will cause the demand for the existing firms to shift to the ________.






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Example: Short and Long Run Equilibrium

A firm in a monopolistic competition produces the level of output at which


A) the marginal revenue equals marginal cost

B) the marginal social cost equals marginal social benefit

C) the demand curve equals the supply curve

D) the marginal revenue equals price



A

MR = MC is true for all market structures. When we plug that output in to the demand the price would higher than the marginal revenue.

Practice: Long Run Equilibrium

What is true of a monopolistically competitive market in long-run equilibrium?

Choose an answer

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Extra Practice

Use the following info to answer the next three questions

A firm operating in a monopolistic competition has the following curves.

In the short run, this firm

A firm in a monopolistic competition produces the level of output at which

The above curves belong to a firm operating in a monopolistic competitive market structure. The above firm is

Which of the following market structures has excess capacity?

In a monopolistic competition, which of the following is true?

Use the following info to answer the question

A firm operating in a monopolistic competition has the following curves.

In the short run, this firm

George is in a monopolistically competitive market, selling cell phone cases. Current he sells 200 cases a day, charging $10 per case and has an average total cost of $10. He just found a clever way to reduce to his average cost to $7.

In the long run

In the long run, firms in a monopolistic competition

A firm in a monopolistic competition produces the level of output at which

In the long run, firms in a monopolistic competition

In the long run, firms in a monopolistic competition

In the long-run in a monopolistically competitive market, each firm will

In the long-run in a monopolistically competitive market, each firm will

In the long-run in a monopolistically competitive market, each firm will

The above curves belong to a firm operating in a monopolistic competitive market structure. What is the long-run price and output level of the firm?

George is in a monopolistically competitive market, selling cell phone cases. Current he sells 200 cases a day, charging $10 per case and has an average total cost of $10. He just found a clever way to reduce to his average cost to $7.

In the long run

Check if true or false

In a monopolistically competitive market, new firms will enter if:

What is true of a monopolistically competitive market in long-run equilibrium?

Which of the following statements are false about a firm in a monopolistically competitive market?

Practice Question: Monopolistic Competition

The market for burgers is a monopolistic competition. The Emin burgers faces the following curves.

1) In the short run, this firm

a) earns a positive economic profit