What is meant by an efficient market equilibrium?

Answer 1

When there is allocative and productive efficiency, there is an efficient market equilibrium, allocative efficiency is when the products that are most wanted are produced, this is achieved when price equals marginal cost, productive efficiency is achieved when the firm is producing on the lowest point on the lowest average cost curve, this is also called the point of technical efficiency, both allocative and productive efficiency lead to an optimum allocation of resources and economic efficiency is achieved, though, this is thought to exist only in a perfectly competitive market and is lacking in other markets because monopolies and oligopolies usually have their prices above marginal cost and that is not an efficient allocation of resources and because other markets may lack the incentive to produce at the lowest cost