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Market Efficiency Concepts

Jul 26, 2025

Overview

This lecture introduces the concepts of efficiency in perfectly competitive markets, focusing on productive and allocative efficiency, and sets up a future comparison with monopolies.

Efficiency in Perfect Competition

  • In the long run, perfectly competitive markets achieve both productive and allocative efficiency.
  • Productive efficiency means firms produce output at the lowest possible cost, minimizing resource waste.
  • Productive efficiency occurs where marginal cost equals minimum average total cost (ATC).
  • Allocative efficiency means firms produce the quantity where the benefit to consumers (willingness to pay) equals the cost to society (marginal cost).
  • In perfect competition, firms produce as long as price (willingness to pay) exceeds marginal cost, stopping when price equals marginal cost.

Productive Efficiency (Review from Chapter 2)

  • Productive efficiency is when firms maximize output with given resources, operating on the production possibility frontier (PPF).
  • No resources are wasted; production is at the minimum point of the average total cost curve.

Allocative Efficiency Explained

  • Allocative efficiency occurs when every unit produced provides greater benefit to society than cost.
  • The market achieves a socially optimal outcome when the price consumers are willing to pay equals marginal cost.
  • Unlike monopolies, perfect competition avoids deadweight loss because all beneficial transactions occur.

Key Terms & Definitions

  • Productive Efficiency — Producing at the lowest possible cost; output is maximized with given resources.
  • Allocative Efficiency — Producing the quantity where consumer willingness to pay equals the marginal cost, ensuring optimal societal benefit.
  • Deadweight Loss — Loss of total surplus that occurs when the market does not produce at allocative efficiency.

Action Items / Next Steps

  • Review definitions of productive and allocative efficiency.
  • Prepare to compare perfect competition with monopoly in the next chapter.