Firm Decisions and Costs Lecture Notes

Jul 23, 2024

Notes on Firm Decisions and Costs

Overview

  • Focus on how firms behave and make decisions regarding costs and prices.
  • Important for students as this is often a challenging part of microeconomics.
  • Course covers Chapters 12, 13, and parts of 14 within one week.

Importance of Studying Firm Decisions

  • Understanding firm decisions is crucial for context in economics.

Statistics on Firms in Canada

  • Definitions of firm sizes:
    • Small Firms: 1 - 99 employees
    • Medium Firms: 100 - 499 employees
    • Large Firms: 500+ employees
  • Small Businesses: 98% of businesses in Canada
  • Medium-sized Firms: 1.9% of Canadian businesses
  • Large Enterprises: 0.2% of Canadian businesses
  • Contribution of small businesses to GDP: 37% in the private sector.
  • Approximately 52,663 establishments in Canada export goods worth over $575 billion.
  • In the U.S., small businesses are 99.7% of all firms, playing a significant role in production and pricing decisions.

Understanding Firm Behavior

Firm Production Function

  • Firms use inputs to create outputs (Q = function of inputs).
  • Inputs include:
    • Raw materials
    • Physical capital
    • Human capital (labor)
  • Focus is on desirable outputs for these chapters.

Marginal Analysis

  • Explore how output changes with the change in one input for ease of analysis (limit to two inputs).
  • Short-run vs. Long-run:
    • Short-run: Capital is inelastic (fixed); firms can only increase labor.
    • Long-run: Both capital and labor can be adjusted.
  • Rule: As long as marginal benefits exceed marginal costs, firms should expand production.

Production Function Example: Wheat Production

  • Firm production function includes inputs like:
    • Natural and manufactured capital
    • Human capital (farmers, labor)
  • Inputs like land are considered fixed inputs that constrain production in the short run.

Total Product and Marginal Product

  • Total Product (TP): Maximum output produced at varying levels of input.
  • The concept of Marginal Product (MP): The change in total product with a unit change in input.
    • MP can increase initially but will begin to diminish.
    • If marginal product becomes zero or negative, firms should not add more inputs.

Production Stages

  • Stages of production include:
    1. Increasing returns
    2. Constant returns
    3. Decreasing returns
  • Economic behaviors may shift or differ across businesses; these stages can change over time.

Production Costs

Types of Costs

  • Fixed Costs: Costs that do not change in the short term and do not vary with production volume (e.g., rent, equipment).
  • Variable Costs: Costs that fluctuate with production levels (e.g., utilities, wages).
  • Break-even point: Where total revenue equals total costs; important for operational decisions.

Cost Formulas

  1. **Total Cost (TC) = Total Fixed Cost (TFC) + Total Variable Cost (TVC)
  2. Average Costs:**
    • Average Fixed Cost (AFC) = TFC / Quantity (Q)
    • Average Variable Cost (AVC) = TVC / Q
    • Average Total Cost (ATC) = TC / Q
  3. Marginal Cost (MC): Change in TC when producing one more unit of output = Change in TC / Change in Q.

Cost Curves

  • Cost curves illustrate relationships between average costs and marginal costs.
  • Marginal cost curves will always intersect the average cost curves at their minimum point.

Summary of Cost Curves

  • Average total cost (ATC) dips then rises in a U-shaped curve.
  • Average variable cost (AVC) follows a similar U-shaped trend but is always below ATC.
  • Marginal cost curves intersect both average cost curves at their respective minimum points.

Example Problem: Costs of Production

  • Fixed costs: $10 (unchanging).
  • Total Costs = TFC + TVC; Average variable cost and average total cost calculations must consider fixed and variable relationships.

Graphs and Charts

  • Important to be able to graph and differentiate between these curves for your assessments.

Key Takeaway

  • Understanding the models and functions of firm behavior, costs, production inputs and outputs is essential in microeconomics for practical applications in business and economic policy.