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Using a well labeled diagram, show and explain why in a perfectly competitive market structure, when the marginal revenue equals marginal cost, this is only...

      

Using a well labeled diagram, show and explain why in a perfectly competitive market structure, when the marginal revenue equals marginal cost, this is only a necessary but not sufficient condition for profit maximization.

  

Answers


Wilfred
The necessary condition for profit maximization is determined at the level of output at which the marginal revenue (MR) is equal to marginal cost (MC): MC = MR level of output.

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To the left of point E1 profit has not been maximized because each unit of output to the left of X1 yields revenue which is greater than marginal cost. To the right of X1 and point E1, each additional unit of output costs more than the revenue earned by its sale, so that the total profit is reduced. The MC curve cuts the MR curve at two points, that is, E0 and E1 . Thus the first condition for the equilibrium of a firm (profit maximization) is that MC = MR. However, this condition is necessary but not sufficient since it may be attained and yet the firm does not maximize profit. In figure 6.1 above, it?s observed that the
necessary condition MC = MR is satisfied at point E0 yet clearly the firm is not maximizing profits.
The second (sufficient) condition for profit maximization requires that the marginal cost (MC) be rising at the point of its intersection with the marginal revenue (MR) curve. This means that the MC curve must cut the MR curve from below, that is , where the slope of the MC curve is greater than the slope of the MR curve. In figure 6.1, the slope of MC curve is positive at E1 while the slope of MR curve is zero at all levels of output.
Thus at E1, both conditions for profit maximization are satisfied: MC = MR and (slope of MC) > (slope of MR). It should be noted that the marginal cost is always positive because the firm must spend some money in order to produce an additional unit of output; Thus, MR is also positive at equilibrium. Economically, if the rate of change in MR is less than the rate of change in MC at the ouput level where MC = MR, then that output will maximize profit (in this case X1 ).
Wilfykil answered the question on February 7, 2019 at 08:47


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