Question

What are differences among perfect competition, monopolistic competition and oligopoly in terms of quantity, market price and profit in short run and long run.

Answer 1

	Perfect competition	Monopolistic	Oligopoly
Quantity	quantity demanded equals quantity supplied	demand equals to the average revenue	demand almost equals the same as of monopolistic firm except there is no need for product differentiation
Market price	the price when quantity equals to supply	marginal cost equals marginal revenue. And solved for the equilibrium price	Price is slightly greater than the marginal cost
Profits in long run and short run	Short run profits is positive. And long run profits are nil	Short run as well as long run profits occur at the profit maximizing condition, i.e. Marginal revenue equals to marginal cost	Due to the significant barriers to entry, oligopolists experience sustained profits in the long run apart from good profits in the short run as well

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