Private Costs And Benefits, Externalities And Social Costs And Benefits (Copy)
7.4.1 Social Costs (SC) and Their Calculation
- Private Costs (PC): Costs borne directly by the producer/consumer of a good.
- External Costs (EC): Costs imposed on third parties not involved in the transaction.
- Social Costs (SC): Total cost to society from production/consumption.
Formula: SC = PC + EC - Marginal Terms:
- Marginal Social Cost (MSC) = MPC + MEC
- Marginal Private Cost (MPC) = Cost to producer of one extra unit.
- Marginal External Cost (MEC) = External cost from one extra unit.
Example Table – Cost Calculation:
| Output (units) | MPC ($) | MEC ($) | MSC ($) |
|---|---|---|---|
| 1 | 5 | 2 | 7 |
| 2 | 6 | 2 | 8 |
| 3 | 7 | 3 | 10 |
7.4.2 Social Benefits (SB) and Their Calculation
- Private Benefits (PB): Benefits received directly by the consumer/producer.
- External Benefits (EB): Benefits enjoyed by third parties.
- Social Benefits (SB): Total benefit to society.
Formula: SB = PB + EB - Marginal Terms:
- Marginal Social Benefit (MSB) = MPB + MEB
- Marginal Private Benefit (MPB) = Benefit to consumer of one extra unit.
- Marginal External Benefit (MEB) = External benefit from one extra unit.
Example Table – Benefit Calculation:
| Output (units) | MPB ($) | MEB ($) | MSB ($) |
|---|---|---|---|
| 1 | 10 | 4 | 14 |
| 2 | 9 | 3 | 12 |
| 3 | 8 | 3 | 11 |
Written and Compiled By Sir Hunain Zia, World Record Holder With 154 Total A Grades, 7 Distinctions and 11 World Records For Educate A Change A2 Level Economics Full Scale Course
7.4.3 Positive and Negative Externalities
- Positive Externality: Third parties receive benefits without paying.
Example: Vaccination → herd immunity. - Negative Externality: Third parties suffer costs without compensation.
Example: Factory pollution affecting nearby residents.
7.4.4 Positive and Negative Externalities of Consumption and Production
Table – Externalities Classification:
| Type | Example | Effect on Society |
|---|---|---|
| Positive Consumption | Education | Increases productivity, social cohesion |
| Negative Consumption | Smoking | Health costs to others |
| Positive Production | Beekeeping | Pollination benefits to farmers |
| Negative Production | Industrial waste | Environmental damage |
7.4.5 Deadweight Welfare Losses
- Deadweight Loss (DWL): Loss of total surplus due to market producing at non-socially optimal output.
- Negative externality: Market overproduces → MSC > MSB → welfare loss triangle to the right of socially optimal point.
- Positive externality: Market underproduces → MSB > MSC → welfare loss triangle to the left of socially optimal point.
Written and Compiled By Sir Hunain Zia, World Record Holder With 154 Total A Grades, 7 Distinctions and 11 World Records For Educate A Change A2 Level Economics Full Scale Course
7.4.6 Asymmetric Information and Moral Hazard
- Asymmetric Information: One party has more/better information than the other, leading to adverse selection.
Example: Used car seller knows defects, buyer does not. - Moral Hazard: One party takes more risks because costs will be borne by another.
Example: Insured driver drives recklessly.
7.4.7 Use of Costs and Benefits in Analysing Decisions
- Compare MSC and MSB to find socially optimal output.
- Decision rule:
- If MSB > MSC → increase output.
- If MSC > MSB → reduce output.
- Used in cost-benefit analysis for policy decisions.
- Net present value (NPV) not required for this syllabus section.