Economic Systems and Market Failure: Question 4

Worked solution

Part (a): Defining private cost and social cost

A private cost is the cost incurred directly by the producer or consumer carrying out an activity. For the festival organiser, this means what they themselves pay for staging, artists and security.

A social cost is the total cost of an activity to society as a whole. It is made up of the private cost plus any external cost. A cost imposed on third parties who are not part of the transaction and who receive no compensation for it.

$\text{social cost} = \text{private cost} + \text{external cost}$

Part (b): Private cost versus social cost at the music festival

The festival organiser’s private cost is the amount they spend putting on the event: staging, artists and security. This is the cost reflected in ticket prices.

However, nearby residents are disturbed by amplified sound and late-night traffic, and they receive nothing in return. This disturbance is an external cost that falls on people outside the transaction between the organiser and ticket-buyers. Because the organiser does not have to pay for the disturbance caused to residents, this external cost is left out of the private cost entirely.

Adding this external cost to the organiser’s private cost gives the true social cost of the festival:

$\text{social cost of festival} = \text{organiser's private cost} + \text{residents' external cost (noise and traffic disturbance)}$

So the social cost of holding the festival is higher than its private cost, because the private cost alone ignores the disturbance imposed on residents.

Part (c): Why the logistics firm under-provides driver training

The logistics firm’s private benefit from training its drivers comes only from what it captures while those drivers remain in its own employment: fewer accidents, less vehicle damage and lower fuel bills. It has no way of billing other companies for the extra safety and efficiency its former drivers carry with them, even though those skills genuinely make those drivers more valuable employees elsewhere. This uncompensated gain to other local delivery firms is an external benefit.

The social benefit of providing an extra unit of training is the firm’s own private benefit (safer, more efficient drivers while they stay) plus this external benefit (safer, more efficient drivers once they move on):

$\text{social benefit of training} = \text{private benefit (to the paying firm)} + \text{external benefit (to future employers)}$

Because the firm can only capture the private benefit when deciding how much training is worth paying for, it will stop increasing training once the private benefit of one more unit of training just covers its private cost. Even though, from society’s point of view, more training would still be worthwhile once the external benefit to other employers is included. The result is that the firm provides less training than the amount that would maximise benefit to society as a whole: an under-provision caused by an external benefit that the market price does not reward.

Final answers

• (a) Private cost = cost borne directly by the producer/consumer; social cost = private cost + external cost.
• (b) The festival’s social cost exceeds its private cost because residents bear an uncompensated external cost (noise and traffic disturbance) on top of the organiser’s own spending.
• (c) The firm under-provides (offers too little) driver training because it is not paid for the external benefit (safer, more efficient drivers) its training later creates for other employers, so it responds only to its own private benefit, which is smaller than the social benefit.