# Relationship between average cost and marginal in the short run pdf

### What is the Relationship between Average Cost and Marginal Cost?

predatory pricing. However, the research on the relationship between average variable cost and short-run marginal cost mainly comes from survey studies. The relationship between average cost and marginal cost can also be studied in the context of laws SAC is the short run average cost curve having U-shape. Understanding the Relationship between Marginal Cost and Average Variable Cost. Review: Marginal cost (MC) is the cost of producing an extra unit of output.

SAC is the short run average cost curve having U-shape. Costs in Long Run Period: Long-run is a period in which there is sufficient time to alter the equipment and the scale or organization with a view to produce different quantities of output.

**Costs of Production- Microeconomics 3.3 (Part 1)**

In other words, if we want to change output, it can be done by changing all the factors. It is due to the reason that in the long-run, all the factors are variable. Long run total cost curve represents the least cost of different quantities of output. Therefore, it is tangent to any given point, on short run total cost.

LTC1 has been drawn on the assumption that as output is increased, cost at first rises at diminishing rate and then at increasing rate.

LTC1 has been drawn on the assumption that increase in output is followed by rise in cost at constant rate.

LTC3 has been drawn on the assumption that as output increases, cost rises at diminishing rate. Long run cost curve always begins from the point of origin while short run cost curve begins from any point on OY-axis. It means that all costs in long run are variable when quantity of output is zero, total costs also reduced to zero.

Long-Run Average Cost Curve: Long-run average cost is the long run total cost divided by the level of output. A given level of output can be had from a special plant to which it is appropriated. If, such a plant is put to operation, goods will be produced at the lowest average cost. Thus, a rational producer in the long- run will choose to produce with the help of such a plant.

Now, the question is how to find out this long-run average cost curve. The answer is very simple. We can derive the LAC from the short-run average cost curves. In Figure 16 long-run average cost has been shown.

### Cost in Short Run and Long Run (With Diagram)

The long- run average cost curve is tangent to different short run average cost curves. Therefore, if a firm is willing to produce OX0 level of output, it will construct a plant corresponding to SAC0 and will operate on this curve at point K. Different Names of LAC: LAC is also known by the following names: As in the long-run indivisible factors can be used to their full capacity, therefore, LAC curve will be surrounding the SAC. It will not cut SAC curves or rise upward. LAC is also known as planning curve.

### Average Cost and Marginal Cost (With Diagrams)

With its help, a firm can plan as to which plant; it should use to produce different quantities of output so that production is obtained at minimum cost. This fact can also be explained with the help of fig. If the firm has to produce OQ1 output, it will select small plant.

So it is the ratio of MC to AC. From the diagram the following relationships can be discovered. These two concepts will be discussed in the context of market structure and pricing. Column 5 shows that average fixed cost decreases over the entire range of output. Instead, the long run simply refers to a period of time during which all inputs can be varied. In order to be able to make this decision the manager must have knowledge about the cost of producing each relevant level of output.

We shall now discover how to determine these long-run costs. For the sake of analytical simplicity, we may assume that the firm uses only two variable factors, labour and capital, that cost Rs. The characteristics of a derived expansion path are shown in Columns 1, 2 and 3 of Table In column 1 we see seven output levels and in Columns 2 and 3 we see the optimal combinations of labour and capital respectively for each level of output, at the existing factor prices.

These combinations enable us to locate seven points on the expansion path. Column 4 shows the total cost of producing each level of output at the lowest possible cost.

For example, for producing units of output, the least cost combination of inputs is 20 units of labour and 10 of capital. At existing factor prices, the total cost is Rs. Here, Column 4 is a least-cost schedule for various levels of production. In Column 5we show average cost which is obtained by dividing total cost figures of Column 4 by the corresponding output figures of Column 1.

Thus, when output isaverage cost is Rs. All other figures of Column 5 are derived in a similar way. From column 5 we derive an important characteristic of long-run average cost: In Column 6 we show long-run marginal cost figures.

Each such figure is arrived at by dividing change in total cost by change in output. For example, when output increases from Rs. Therefore, marginal cost per unit is Rs. We may now show the relationship between the expansion path and long-run cost graphically. Finally, the known production function gives us the isoquant map, represented by Q1, Q2 and so forth. We may now relate this expansion path to a long-run total cost LRTC curve.

For example, in Fig. Every other point on LRTC is derived in a similar way. Thus, totally different production processes may be used to produce say Q 1 and Q2 units of output at the lowest attainable cost. On the basis of this diagram we may suggest a definition of the long run total cost.

## What is the Relationship between Average Cost and Marginal Cost? – Explained!

First, costs and output are directly related; that is, the LRTC curve has a positive slope. But, since there is no fixed cost in the long run, the long run total cost curve starts from the origin. Since the slope of the total cost curve measures marginal cost, the implication is that long-run marginal cost first decreases and then increases. It may be added that all implicit costs of production are included in the LRTC curve.

Long-Run Average and Marginal Costs: We turn now to distinguish between long run average and marginal costs.

Long-run average cost is arrived at by dividing the total cost of producing a particular output by the number of units produced: They have essentially the same shape and relation to each other as in the short run. The marginal cost intersects the average cost curve at its lowest point L in Fig.

Actually, MC rises earlier than AC. Here, MC stands equal to AC, i. It brief, it can be said that MC intersects AC at its minimum point. Both are U-shaped curves on account of the operation of the law of variable proportions. When MC rises above AC, it pulls the latter upwards. Here, the ray from the origin is also tangent to the corresponding point of total variable cost curve.