Unit 1: The Firm and Perfect Market Structure
Course Code: ECODSM 251/252 (Principles of Microeconomics)
This unit transitions from basic economic concepts to the application of demand, supply, and cost in understanding the functioning of market systems and specifically the perfect competition structure.
Table of Contents
1. Objectives of Firms
In microeconomics, a firm is a technical unit that transforms inputs into outputs. While various objectives exist, the traditional assumption in competitive analysis is profit maximization.
- Primary Objective: Profit Maximization (Total Revenue - Total Cost).
- Secondary Objectives: Sales maximization, market share growth, or social responsibility (corporate governance).
2. Behaviour of Profit Maximizing Firms
A profit-maximizing firm makes decisions regarding output levels and input combinations to achieve the largest possible surplus of revenue over costs.
The Profit Maximization Rule: A firm will continue to produce as long as Marginal Revenue (MR) = Marginal Cost (MC).
- If MR > MC: The firm should increase production to gain more profit.
- If MR < MC: The firm should decrease production to avoid losses on marginal units.
3. The Production Process
The production process involves the combination of various inputs (Factors of Production) to create a final product or service.
- Inputs: Land, Labour, Capital, and Entrepreneurship.
- Technology: The method or knowledge used to combine these factors efficiently.
- Production Function: The mathematical relationship between the maximum output achievable from a given set of inputs.
4. Market and Classification of Market Structures
A market is a mechanism where buyers and sellers interact to exchange goods and services. Market structures are classified based on the level of competition.
| Market Structure | Number of Firms | Nature of Product | Ease of Entry |
|---|---|---|---|
| Perfect Competition | Very Large Number | Homogeneous (Identical) | Free Entry/Exit |
| Monopoly | One | Unique (No close substitutes) | Blocked |
| Monopolistic Competition | Large Number | Differentiated | Easy |
| Oligopoly | Few | Homogeneous or Differentiated | Difficult |
5. Perfect Competition: Short-run and Long-run Equilibrium
Perfect competition is a theoretical market structure where firms are price-takers.
Short-run Equilibrium
In the short run, at least one factor of production is fixed. Firms can earn:
- Supernormal Profit: Price (AR) > Average Cost (AC).
- Normal Profit: Price (AR) = Average Cost (AC).
- Loss: Price (AR) < Average Cost (AC).
Long-run Equilibrium
In the long run, all factors are variable, and there is free entry and exit.
- If firms earn supernormal profits, new firms enter, increasing supply and lowering prices.
- If firms suffer losses, some firms exit, decreasing supply and raising prices.
- Final Result: All firms earn only Normal Profits where Price = MC = Minimum LAC.
6. Economic Efficiency and Perfect Competition
Perfect competition is considered the benchmark for economic efficiency.
- Allocative Efficiency: Occurs when Price = Marginal Cost (P=MC). The value consumers place on the last unit equals the cost of producing it.
- Productive Efficiency: Occurs when firms produce at the minimum point of their Average Cost (AC) curve in the long run.