Characteristics of monopolistic competition

Monopolistic competition describes a market structure that combines elements of both perfect competition and monopoly.

Key features of monopolistic competition

• Position on the market structure spectrum - It falls between perfect competition and monopoly, alongside oligopoly.
• Product differentiation - Products are similar but not identical, either due to advertising or real differences.
  • This gives firms some control over pricing, leading to a downward-sloping demand curve.
  • The degree of differentiation affects price elasticity: smaller differences make demand more elastic.
• Barriers to entry - These are low or non-existent, allowing new firms to enter the market easily.
• Relevance to real-life markets - These conditions reflect many everyday industries.

Short-run equilibrium in monopolistic competition

In the short run, firms in monopolistic competition can earn supernormal profits due to product differentiation and limited entry barriers, similar to a monopoly.

Profit-maximising position in the short run

Firms maximise profits where marginal cost (MC) equals marginal revenue (MR):

• The demand curve (also average revenue, AR) slopes downwards because of product differentiation.
• The MR curve is steeper and lies below the demand curve.
• Output is set at the quantity where MC = MR, and price is read from the demand curve at that quantity.
• If price exceeds average cost (AC) at this output, the firm earns supernormal profit.

Demand is more price elastic than in a monopoly due to substitute products, but supernormal profits are still possible temporarily.

Long-run equilibrium in monopolistic competition

Over time, low barriers to entry erode short-run supernormal profits, leading to a position closer to perfect competition where only normal profits are made.

Adjustments leading to long-run equilibrium

• New firms enter the market attracted by supernormal profits, shifting existing firms' demand curves leftwards as market share is divided.
• Entry continues until supernormal profits disappear, reaching equilibrium where price equals AC (normal profit).
• At this point, the demand curve is tangent to the AC curve (they touch but do not cross).
• At this quantity, MR = MC.
• The firm does not produce at the lowest point of the AC curve, so it is not productively efficient.
• Price exceeds MC, indicating a lack of allocative efficiency.
• Despite inefficiencies, this structure is generally more efficient than a monopoly.

Comparison of prices in monopolistic competition with other market structures

Prices in monopolistic competition are influenced by the need for differentiation and the speed of new entry, positioning them between those in perfect competition and monopoly.

Factors affecting prices in monopolistic competition

• Short-run vs long-run dynamics - Short-run prices can be high like a monopoly, but new entrants drive them down to normal profit levels; the speed of entry determines how long high prices persist.
• Efforts to maintain pricing power - Firms invest in differentiation (e.g., advertising or innovation) to prolong supernormal profits and delay entry.
• Comparison with perfect competition - Prices are higher because firms operate above the minimum AC point and incur costs for differentiation (e.g., branding).
• Restricted output - Firms limit production to maximise profits, missing some economies of scale.
• Comparison with monopoly - Prices are generally lower due to competition from entrants and substitutes.
• Overall assessment - Monopolistic competition often results in reasonable market outcomes in practice.

Dynamic efficiency in monopolistic competition

Dynamic efficiency involves improvements in productivity and innovation over time, but monopolistic competition offers limited incentives for significant investment.

Reasons for limited dynamic efficiency

• Short duration of supernormal profits - Low entry barriers mean profits are quickly competed away, reducing the reward for risky investments in new products or processes.
• Impact on innovation - Firms are less likely to invest huge amounts of money on new innovations.
• Long-run constraints - In the long run, the absence of supernormal profit means there won't be much money available for investment.