Firms in Perfectly Competitive Markets

Perfectly Competitive Markets

• Definition: A perfectly competitive market is characterized by:

  • Many buyers and sellers
  • Identical products offered by all firms
  • No barriers to entry or exit for new firms

• Price Takers: In this market type, firms cannot influence the price and instead accept the market price due to their relatively small size.

• Demand Curve: Perfectly competitive firms face a horizontal demand curve, as they have to take the market price as given. For example, a wheat farmer receives the same price regardless of the quantity they sell.

Maximizing Profit in Perfectly Competitive Markets

• Profit Maximization Objective: All firms aim to maximize profit. Profit is defined as:
  \text{Profit} = \text{Total Revenue} - \text{Total Cost}

• Average Revenue (AR): For perfectly competitive firms, AR is equal to the price:

  • AR = \frac{\text{Total Revenue}}{Q} \rightarrow AR = P (where Q is quantity produced)

• Marginal Revenue (MR): The additional revenue from selling one more unit:

  • MR = \frac{\Delta TR}{\Delta Q}

• Output Decision: To maximize profit, firms produce where:

  • MR = MC (Marginal Cost)
  • For perfectly competitive firms, this is also where P = MC .

Profit or Loss Illustration

• Graphs:

  • Use graphs to visualize total revenue and total cost, identifying points of maximum profit or loss based on the vertical distance between the curves.
  • Profit per unit can be illustrated as the difference between price and average total cost (ATC):
    \text{Total Profit} = (P - ATC) \cdot Q

• Deciding on Production vs. Shutdown:

  • A firm should continue to produce if it can at least cover variable costs. If:
  • P < AVC , shut down temporarily.
  • Consider sunk costs, such as fixed costs, when making this decision.

Long-Run Dynamics in Perfect Competition

• Entry and Exit:

  • Economic Profit: Attracts new firms into the market, increasing supply and driving prices down.
  • Economic Loss: Causes existing firms to exit, reducing supply and pulling prices back up to the profit level.
  • Firms will reach a long-run equilibrium where P = ATC, resulting in zero economic profit.

• Long-Run Supply Curve:

  • In perfectly competitive markets, the long-run supply curve is horizontal at the minimum point of the ATC curve, allowing prices to adjust to consumer demand at the lowest production cost.

Efficiency in Perfect Competition

• Types of Efficiency:

  • Productive Efficiency: Achieved when goods are produced at the lowest cost. In long-run equilibrium, P = ATC ensures this.
  • Allocative Efficiency: Achieved when resources are distributed according to consumer preferences where:
  1. Price reflects the marginal benefit consumers receive.
  2. Production continues until marginal cost equals marginal revenue, ensuring the last unit produced is valued accurately by consumers.

• Conclusion: Perfect competition not only ensures firms operate effectively but also meets consumer needs efficiently.

Real-World Examples

• Cage-Free Eggs Case:
  • As farmers began producing cage-free eggs for higher prices, new entrants entered the market leading supply to increase, eventually lowering prices down to levels where only normal profits could be earned.
  • The shift from cage-free to pasture-raised eggs illustrates how market dynamics can lead to new innovations and adjusted production as firms adapt.