A perfectly competitive market is considered one where perfect information exists (in other words, a hypothetical extreme market) that operates in the most desirable state possible. In the short run, super normal profits (the extra profit that is considered above the normal profit level) or losses are to be expected. In the long run, the super normal profits created in the short run attract new businesses to enter into the market; supply will increase and the market price will decrease until only normal profit is attainable. Firms will adapt to the market changes in the short run by adjusting their output quantity to where their profits are the highest.By adjusting the production output to the marginal cost over time, a profit is still achievable. If the adjustment is not made, there will be a loss in profits. Perfectly competitive firms can expect other players to enter the market, which will increase the supply and decrease the market price. In order to maximize profits, the firm should set their marginal revenue to equal marginal cost.