Why does marginal cost equal supply

Graph 31 Impact of Technology. An advance in production technology increases supply which puts downward pressure on the market price for the product. Firms that do not adopt the new production technology will experience reduced revenue but without an offsetting reduction in cost.

This relation is described in the determinents of supply , but now we have an understanding of the intermediate steps that lead to that outcome. The next section explains strategies a manager may pursue when the business is unprofitable. Agriculture Law and Management Accessibility. Info Share. The firm's supply of output is revealed from the firm's marginal cost curve. Marginal Cost as the Supply of Output This page describes a relationship between a firm's marginal cost curve MC and the firm's supply of the the output.

Choices Are Made at the Margin. Microeconomics and Macroeconomics. Putting Economics to Work. Careers in Economics. Models in Economics. Testing Hypotheses in Economics. The Fallacy of False Cause. Review and Practice Summary. Confronting Scarcity: Choices in Production. Natural Resources. Constructing a Production Possibilities Curve. Comparative Advantage and the Production Possibilities Curve.

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Prices of Factors of Production. Returns from Alternative Activities. Seller Expectations. Natural Events. The Number of Sellers Heads Up! Case in Point: The Monks of St. The Determination of Price and Quantity. Shifts in Demand and Supply. An Increase in Demand. A Decrease in Demand. An Increase in Supply. A Decrease in Supply Heads Up! Simultaneous Shifts. Case in Point: Demand, Supply, and Obesity. Applications of Demand and Supply. The Personal Computer Market.

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Economic Profit in the Short Run. Economic Losses in the Short Run. Producing to Minimize Economic Loss. If the firms all had the same cost functions, they would have identical supply functions; if not, their supply functions will differ. The quantity supplied to the whole market at price is:. The function is the market supply function.

The graph of this function, typically drawn with on the vertical axis and on the horizontal, is the market supply curve. Graphically, the process of going from the supply curves of individual firms to that of the whole market can be viewed as aggregation in the horizontal direction; at any particular price, the individual supplies are added up to give the market supply. In Figure 1, we have drawn the market supply in the right-hand panel, on the assumption that there are 50 bakeries with identical supply functions.

So at each price, market supply is 50 times the individual firm supply. As we discussed in the text, the market supply curve can be interpreted as the marginal cost curve for the market as a whole. It gives the minimum price at which sellers are willing to supply a given amount of the good. Since each firm chooses a level of output where price equals marginal cost, each firm that produces a positive amount of output must have the same marginal cost. The market supply curve measures the relationship between total output and the common marginal cost of producing this output.

The interpretation of the market supply curve as a marginal cost curve is one reason for the standard practice of drawing supply curves with on the vertical axis. Read more: Section 7. Mathematics for economists: An introductory textbook , 4th ed. Manchester: Manchester University Press. This ebook is developed by the CORE project.