Principles of Microeconomics: A Firm's Production Decisions and Costs Summary

Firm and Its Types

• Definition: A business organization that hires and organizes factors of production to sell goods and services.

• Types of firms:

  • Sole Proprietorship: Owned by one individual, responsible for all firm activities.

  • Partnership: Joint ownership by two or more individuals; limited partnerships allow non-managing partners.

  • Corporation: Owners are not personally liable for debts; operations are managed by others.

  • State-owned Enterprise: Owned by the government, managed by officials.

  • Nonprofit Organization: Provides goods/services without profit intent.

Costs Measurement

• Explicit Costs: Actual monetary payments made.

• Implicit Costs: Opportunity costs of owner’s resources without direct monetary payments.

• Accounting Profit: Total Revenue - Total Explicit Costs.

• Economic Profit: Total Revenue - Total Costs (includes both explicit and implicit).

• Normal Profit: Minimum profit to keep the entrepreneur engaged.

• Sunk Cost: Historical costs that cannot be recovered, irrelevant for decision-making.

Production Concepts

• Short Run: Time period where at least one input is fixed.

• Total Product: Total output from the production process.

• Marginal Product (MP): Increase in total product from adding one more unit of input. Formula: $MPL = \frac{\Delta TP}{\Delta L}$

• Average Product (AP): Total product divided by quantity of inputs. Formula: $APL = \frac{TP}{L}$

• Law of Diminishing Returns: Increases in variable input lead to diminishing output increases after a certain point.

Costs Definitions

• Total Fixed Costs (TFC): Costs that do not change with output level.

• Total Variable Cost (TVC): Costs that change with output.

• Average Total Cost (ATC): Total cost divided by output. Formula: $ATC = \frac{TC}{total\ output}$

• Marginal Cost (MC): Change in total costs due to producing one more unit. Formula: $MC = \frac{\Delta TC}{\Delta total\ output}$

Cost Reduction Strategies

• Cost cutting targets average costs rather than total costs.

• Average costs decrease if:

  • Price of inputs falls.

  • Technology improves improving marginal productivity.

  • Firms increase output when operating under capacity or decrease when over.

Key Concepts Summary

1. Distinction between explicit and implicit costs.

2. Difference between normal and economic profit.

3. Concepts of total product, average product, and marginal product.

4. Division of labor and law of diminishing returns.

5. Understanding total, variable, and fixed costs.

6. Relationships among different product and cost curves.