Economics 9708/32 — October/November 2022

Background Concept

Allocative efficiency occurs when resources are distributed in a way that maximises the net benefit to society. In a market, this is achieved when the price consumers are willing to pay equals the marginal cost of production (P = MC). At this point, the value of the last unit produced to society equals the cost of producing it, and there is no deadweight loss. Perfect competition is often associated with allocative efficiency in the long run because firms are price takers and produce where P = MC. In contrast, market structures such as monopoly or oligopoly tend to produce less output and charge a higher price (P > MC), leading to allocative inefficiency.

Understanding the Question

This multiple-choice question asks which of four options is most likely to improve allocative efficiency. The command is implicit: identify the factor that moves the market closer to P = MC. The options are all market structure changes: a higher concentration ratio (A), collusion (B), entry of new firms (C), and mergers (D). The correct answer must be the one that increases competition, because competition forces price down toward marginal cost.

Approach

Recall the definition of allocative efficiency (P = MC). Then evaluate each option in terms of its effect on competition and the price-cost margin. The option that increases competition will improve allocative efficiency; those that reduce competition will worsen it.

Step-by-Step Reasoning

1. Option A: a higher market concentration ratio – This means fewer firms dominate the market. Higher concentration reduces competition, allowing firms to set price above MC, so allocative efficiency worsens.

2. Option B: collusion between firms – Collusion (e.g., forming a cartel) enables firms to act like a monopolist, restricting output and raising price above MC. This clearly reduces allocative efficiency.

3. Option C: entry of new firms into the market – New entrants increase the number of competitors. This erodes market power, drives down price, and pushes it closer to marginal cost. In the long run, if entry is free, the market may approach the perfectly competitive outcome where P = MC, improving allocative efficiency.

4. Option D: mergers of firms – Mergers reduce the number of independent firms, increasing concentration and market power. This enables the merged entity to raise price above MC, worsening allocative efficiency.

Thus, only option C is likely to improve allocative efficiency.

Key Takeaways

• Allocative efficiency requires P = MC.
• Competition is the primary mechanism that forces price toward MC.
• Any factor that reduces competition (higher concentration, collusion, mergers) harms allocative efficiency.
• Entry of new firms is a key competitive force.

Common Mistakes

• Confusing productive efficiency (producing at minimum average cost) with allocative efficiency. Productive efficiency is about cost minimisation, while allocative efficiency is about the correct mix of output.
• Thinking that larger firms are always more efficient. While they may achieve economies of scale, they often have market power and charge higher prices, worsening allocative efficiency.

Things to Be Careful About

• The question asks for the option most likely to improve allocative efficiency. In some contexts, entry might not immediately improve efficiency if the market is already contestable, but generally it is the strongest pro-competitive force among the options.
• The concept of allocative efficiency is often tested in multiple-choice questions, and the answer typically hinges on the degree of competition.