Perfect Competition

Definitions and Characteristics of Perfect Competition

  • Perfect or Pure Competition: The purest form of market structure characterized by the following elements:

    • Large number of sellers (producers).

    • Production of a standardized (homogenous) product.

  • Price Takers: Sellers in perfectly competitive markets cannot influence the market price and accept the price as given.

  • Ease of Entry and Exit: Producers can enter or leave the market without significant barriers.

Example: Market for Tomatoes at a Farmer's Market

  • Large Number of Sellers: Clara and many other producers exist in the market.

    • Oscar’s choice: Can buy tomatoes from Clara or various other sellers.

    • Local competition with many producers, thousands nationwide.

  • Standardized Product: All sellers offer virtually identical tomatoes, such as Roma or Cherry.

    • Consumers (like Oscar) perceive them as perfect substitutes, leading to indifference in purchasing.

  • Price Takers: Sellers must sell their tomatoes at market-determined prices.

    • If Clara raises her price above market rate, customers would buy from others instead.

    • Selling below market rate would decrease her profits.

  • Ease of Market Dynamics: Producers can quickly switch between products, e.g. Clara could transition from tomatoes to peppers, or Emma could enter the tomato market easily.

Summary of Characteristics of Perfectly Competitive Markets

  • Key Features:

    • Numerous sellers and standardized products.

    • Sellers are price takers with little to no market influence.

    • Minimal restrictions on market entry and exit.

  • Market Analysis Context: Although rare in real-world markets, perfect competition serves as a fundamental starting point for economic analysis regarding efficiency, pricing, and quantities in different market structures.

Demand and Revenue in Perfectly Competitive Markets

  • Market Price Determination: For perfectly competitive firms, price equals the overall market equilibrium price.

    • Each unit sold generates revenue equal to the market price.

  • Representation of Demand Curve: In graphical analysis, demand for a perfectly competitive firm's output appears as a horizontal line at market price.

    • Example: At equilibrium price of $3 per pound for tomatoes, every pound sold yields $3 in revenue (CRUD: Constant Revenue User Demand).

  • Marginal Revenue and Average Revenue:

    • Marginal Revenue (MR): Revenue from selling one more unit, equal to the market price ($3), remaining constant.

    • Average Revenue (AR): Total revenue per unit sold; equals price in perfect competition.

  • Graphical Representation: With price on the vertical axis and quantity on the horizontal:

    • Demand and MR curves show horizontal lines coinciding with the market price.

Market Adjustments in Perfectly Competitive Firms

  • Response to Change in Market Demand:

    • Increase in Demand: Shifts demand curve right, increasing equilibrium price.
      - Example Increase: Demand shift from D1 to D2 results in new price P2, leading to higher MR.
      - Firm increases output to Q2 where MR2 meets MC.

    • Decrease in Demand: Shifts demand curve left, decreasing price.
      - Example Decrease: Market demand shifts back to lower price P3.
      - Firm reduces output to Q3 where MR3 equals MC.

Profit Maximizing Behavior of Perfectly Competitive Firms

  • Profit Maximization Rule: Firms maximize profits where marginal cost (MC) equals marginal revenue (MR).

    • Calculating Profit:

      • Total Revenue (TR) = Price × Quantity

      • Total Profit = Total Revenue (TR) - Total Cost (TC)

      • Per Unit Profit = Price - Average Total Cost (ATC)

Graphical Illustration of Firm Profit/Loss Scenarios

  • Profits and Losses Representation:

    • If price equals ATC, firm makes zero economic profit (normal profit).

    • Price above ATC results in economic profits represented in orange areas of a graph.

    • Price below ATC indicates dat an economic loss occurs.

Short Run Decisions in the Event of Losses

  • Short Run Production Decision:

    • If price (P2) covers variable costs but not fixed costs, firm continues to produce (operation at loss).

    • Key Consideration: If price (P2) is below average variable costs (AVC), the firm should shutdown.

Understanding Supply Curve in Perfectly Competitive Firms

  • Deriving the Supply Curve:

    • Supply curve derived from the portion of the marginal cost curve above AVC:

      • If market price is below AVC, the firm will produce zero output.

Long Run Equilibrium in Perfectly Competitive Markets

  • Market Adjustments Over Time:

    • Short-run profits attract new entrants, shifting the market supply to the right, thus lowering the price until only normal profits prevail.

    • Economic fluctuations incentivize exit or entry based on profitability; losses prompt exit while profits invite entry.

  • Long Run Stability: Final equilibrium leads to an environment where firms make normal profits with efficient production at minimum ATC levels.

    • Allocative and Productive Efficiency: Market outcomes ensure total surplus is maximized, balancing consumer and producer surpluses.

Effects of Demand Shifts on Supply and Market Price in Constant Cost Industries

  • Increasing Demand: Raises market price temporarily until new firms enter, driving price back.

  • Decreasing Demand: Lowers market price leading to exits and balancing supply and price over the long run.

Types of Industries Based on Cost Behavior

  • Constant Cost Industry: Production costs remain unchanged with expanded output.

  • Increasing Cost Industry: Production costs rise as production increases (upward sloping supply curve).

  • Decreasing Cost Industry: Production costs decrease with increased output (downward sloping supply curve).