Understanding Scale: Economies, Diseconomies, and MES

1. Economies of Scale: The Benefits of Getting Bigger

As we touched on previously, economies of scale occur when a firm's long-run average cost per unit of production decreases as its output increases. This is the downward-sloping portion of the LRAC curve.

But why does this happen? The reasons can be grouped into two categories: internal and external.

• Internal Economies of Scale: These are cost advantages that arise from the growth of the firm itself. They are unique to the firm and within its control.
• External Economies of Scale: These are cost advantages that any firm in an expanding industry can benefit from, regardless of its own size. They are due to factors outside the firm's direct control.

To explore the specific factors that create these economies, let's watch a detailed breakdown.

To summarize and reinforce what you just watched:

Key Drivers of Internal Economies of Scale

As a firm grows, it can:

• Technical: Invest in more efficient, large-scale machinery and technology that would be too costly for a small-scale operation. Think of an automated assembly line in a large car factory versus the hand tools used in a small garage.
• Managerial: Employ specialist managers (e.g., in finance, marketing, logistics). Their expertise can increase productivity across the firm, and their salaries are spread over a much larger output.
• Financial: Secure loans from banks at lower interest rates. Larger, more established firms are seen as less risky, giving them access to cheaper capital.
• Purchasing (or Bulk-Buying): Negotiate significant discounts from suppliers by buying raw materials and components in large volumes.
• Marketing: Spread the high fixed costs of a national advertising campaign over a vast number of units sold, lowering the marketing cost per unit.
• Risk-Bearing: Diversify into different products and markets. A downturn in one area can be offset by stability in another, reducing the overall risk and cost of capital for the firm.

Key Drivers of External Economies of Scale

As an entire industry grows in a specific region, firms within it benefit from:

• Improved Infrastructure: Local governments may build better roads, ports, or communication networks to support the industry, reducing transport and logistics costs for all firms.
• Supplier Clustering: Component suppliers and specialized service providers may relocate closer to the industry's hub, reducing shipping times and costs for firms.
• Skilled Labor Pool: Universities and colleges may start offering specialized training programs relevant to the local industry, creating a readily available pool of skilled workers.

2. Diseconomies of Scale: The Problems of Getting Too Big

If economies of scale continued forever, we would end up with a single giant firm in every industry. This doesn't happen because firms eventually encounter diseconomies of scale, where long-run average costs begin to increase as output rises. This corresponds to the upward-sloping part of the LRAC curve.

These are almost always internal issues that stem from the challenges of managing an overly large and complex organization.

Let's return to the video to see the common causes of these inefficiencies.

The main causes of diseconomies of scale, as the video explained, are managerial and organizational:

• Control & Coordination: It becomes increasingly difficult to monitor thousands of employees and coordinate complex operations across numerous departments and locations. This can lead to duplication of effort and operational slack.
• Communication: In a large bureaucracy, information flows slowly. Messages can be distorted as they pass through long chains of command, leading to poor decision-making and a lack of agility.
• Motivation: Individual employees may feel alienated and less valued in a giant corporation. This can reduce morale and productivity, as workers feel their individual efforts have little impact.

3. Minimum Efficient Scale (MES)

We now have a complete picture: firms first enjoy falling average costs (economies of scale), and then experience rising average costs (diseconomies of scale). The point of transition is critically important.

The Minimum Efficient Scale (MES) is the lowest level of output at which a firm can minimize its long-run average cost. It is the point where the firm has fully exploited all economies of scale, just before diseconomies begin to set in.

Graphically, it's the bottom of the U-shaped LRAC curve.

The MES is not just a theoretical point; it has profound practical implications for how an industry is structured.

To understand this connection, please watch the next video.

As the video explained, the relationship between MES and the total market demand is a key determinant of market structure:

• Low MES relative to market size: If a firm can achieve minimum efficient scale at a low level of output (e.g., a local restaurant), the market can support many efficient firms. This leads to a fragmented market with a high degree of competition.
• High MES relative to market size: If a firm must produce a very large quantity to minimize its average costs (e.g., an aircraft manufacturer), the market may only be able to support a few large firms or even just one. This leads to a concentrated market (oligopoly or monopoly). The extreme case, where MES is close to or larger than total market demand, can result in a natural monopoly.

A Note on Calculating MES

While you won't be required to perform complex calculus on the CFA exam, it's useful to know the economic principle for identifying the MES. The minimum point of the Long-Run Average Cost (LRAC) curve occurs where the Long-Run Marginal Cost (LRMC) curve intersects it.

MES is achieved at the output level where: LRMC = LRAC

This is because as long as the cost of producing one more unit (LRMC) is below the average cost (LRAC), it pulls the average down. Once the cost of the next unit is above the average, it starts to pull the average up. The average is at its minimum precisely where the two are equal.

Let's reinforce this with a simple numerical example, similar to the one in the WallstreetMojo article you have available.

Suppose a firm's long-run average cost is given by the function:
$LRAC=100-4Q+0.05Q^2$
And its long-run marginal cost is:
$LRMC=100-8Q+0.15Q^2$

To find the output level (Q) that corresponds to the MES, we set LRMC equal to LRAC:
$100-8Q+0.15Q^2=100-4Q+0.05Q^2$

Now, we solve for Q:
$0.10Q^2-4Q=0$
Factor out Q:
$Q(0.10Q-4)=0$
This gives two solutions, Q=0 (which is trivial) and:
$0.10Q-4=0$
$0.10Q=4$
$Q=40$

Therefore, this firm achieves its minimum efficient scale at an output level of 40 units.

Conclusion

In this lesson, we moved from describing the LRAC curve to explaining the economic forces that shape it. Understanding these concepts is fundamental to analyzing a firm's strategy and its competitive environment.

Key Takeaways:

• Economies of Scale cause LRAC to fall as output increases, driven by internal factors (specialization, bulk-buying) and external factors (industry growth).
• Diseconomies of Scale cause LRAC to rise as output increases, typically due to internal managerial challenges like poor communication and control in overly large firms.
• The Minimum Efficient Scale (MES) is the output level that minimizes LRAC. It represents the most productively efficient size for a firm.
• The ratio of a firm's MES to total market demand is a strong indicator of market structure. A low ratio suggests a competitive market, while a high ratio suggests a concentrated market (oligopoly or monopoly).

Preview of the Next Lesson:

We have now thoroughly examined the cost side of a firm's operations. To understand how a firm makes its ultimate decision on how much to produce, we must also consider the revenue it earns. In our next lesson, we will introduce the concept of marginal revenue and bring it together with marginal cost to establish the profit-maximizing rule (MR=MC), a cornerstone of microeconomic analysis.