Perfect Competition - Basic Structural Characteristics

Basic Structural Characteristics

Generally, a perfectly competitive market exists when every participant is a "price taker", and no participant influences the price of the product it buys or sells. Specific characteristics may include:

• Infinite buyers and sellers – An infinite number of consumers with the willingness and ability to buy the product at a certain price, and infinite producers with the willingness and ability to supply the product at a certain price.
• Zero entry and exit barriers – A lack of entry and exit barriers makes it extremely easy to enter or exit a perfectly competitive market.
• Perfect factor mobility – In the long run factors of production are perfectly mobile, allowing free long term adjustments to changing market conditions.
• Perfect information - All consumers and producers are assumed to have perfect knowledge of price, utility, quality and production methods of products.
• Zero transaction costs - Buyers and sellers do not incur costs in making an exchange of goods in a perfectly competitive market.
• Profit maximization - Firms are assumed to sell where marginal costs meet marginal revenue, where the most profit is generated.
• Homogenous products - The qualities and characteristics of a market good or service do not vary between different suppliers.
• Non-increasing returns to scale - The lack of increasing returns to scale (or economies of scale) ensures that there will always be a sufficient number of firms in the industry.
• Property rights - Well defined property rights determine what may be sold, as well as what rights are conferred on the buyer.

In the short run, perfectly-competitive markets are not productively efficient as output will not occur where marginal cost is equal to average cost (MC=AC). They are allocatively efficient, as output will always occur where marginal cost is equal to marginal revenue (MC=MR). In the long run, perfectly competitive markets are both allocatively and productively efficient.

In perfect competition, any profit-maximizing producer faces a market price equal to its marginal cost (P=MC). This implies that a factor's price equals the factor's marginal revenue product. It allows for derivation of the supply curve on which the neoclassical approach is based. This is also the reason why "a monopoly does not have a supply curve". The abandonment of price taking creates considerable difficulties for the demonstration of a general equilibrium except under other, very specific conditions such as that of monopolistic competition.