The Depth and Width of Moats
Quick definition: Moat depth measures how much pricing power a company possesses; moat width measures how many markets or customer segments are protected by that advantage. The strongest moats score high on both dimensions.
Not all moats are created equal. Two companies might both possess genuine competitive advantages, yet one will generate far greater wealth for investors. The difference often lies in how you assess the moat along two critical dimensions: depth and width.
Depth determines how much of the economics—how much excess return above the cost of capital—the company can capture. Width determines how large the addressable market is where that depth applies. A narrow, deep moat in a small market creates less value than a wide, moderately deep moat in a massive market. Understanding both dimensions separates precise valuation from guesswork.
Moat Depth: The Measure of Pricing Power
Depth is the vertical dimension of a moat. It answers the question: How much can the company raise prices before customers defect or competitors gain share?
A deep moat grants enormous pricing power. The customer's cost of switching is so high, or the company's differentiation is so clear, that the company can increase prices well above the rate of inflation without losing significant volume. Shallow moats permit minimal pricing power. Any price increase above what cheaper alternatives offer will cause customers to leave.
Network effects create deep moats. When a customer's value from a product increases with the size of the network, switching costs are near-infinite. Facebook can charge advertisers substantial premiums for access to its network; there is no close substitute. A new social network, no matter how superior its technology, enters with zero network value and cannot compete on price because the network effect disadvantage is absolute.
Brand loyalty creates depth when it reflects genuine willingness to pay. Coca-Cola can raise prices for its signature cola; customers will pay because the brand preference is real. However, if brand preference is fragile—dependent on temporary trends or nostalgia—depth is shallow. The company that relies on being "cool" one year and obsolete the next does not possess a deep moat.
Switching costs create depth proportional to the cost size. If switching from one enterprise software vendor to another requires retraining staff, migrating data, and disrupting operations, the switching cost might equal 20 percent of the annual license fee. The vendor can raise prices by 15 percent and the customer still saves money by staying. The moat depth is measured by the gap between current pricing and the switching cost threshold.
Economies of scale create depth through cost advantage. If a company can produce a unit at $5 while competitors' unitary costs are $8, it can price at $7 and still maintain superior unit economics. However, if the cost difference is $5 versus $5.50, the depth is shallow. The company must maintain volume to preserve the advantage, and it cannot raise prices substantially without enabling competitors to reach scale and close the cost gap.
Switching costs in consumer products are typically shallow. A consumer can switch from one laundry detergent to another by buying a different bottle at the next shopping trip. Switching costs are measured in dollars or seconds, not thousands of dollars or months. Therefore, even dominant consumer brands often have limited pricing power. They can maintain margins through volume and operational efficiency, not by raising prices dramatically.
Measuring Depth: The ROIC Framework
The most objective measure of moat depth is return on invested capital (ROIC) relative to the cost of capital.
If a company generates ROIC of 25 percent while its cost of capital is 10 percent, the moat is deep. The company earns 15 percentage points of excess return—a spread that reflects genuine competitive advantage. If ROIC is 12 percent and cost of capital is 10 percent, the moat is shallow. The excess return is only 2 percentage points, and a modest increase in competition would eliminate it.
The persistence of ROIC spread over time reinforces this assessment. A company that maintains 15 points of excess return for ten consecutive years possesses a deep, durable moat. A company whose spread narrows from 15 points to 5 points over five years is experiencing moat erosion, and depth is declining.
For growth investors, the ROIC framework offers clarity. A high-growth company with mediocre ROIC (equal to or below cost of capital) is not building a moat. It is burning capital to achieve growth that creates no value. A lower-growth company with exceptional ROIC is building moat depth with every reinvested dollar.
Moat Width: The Measure of Market Scope
Width is the horizontal dimension of a moat. It answers the question: How many markets, customer segments, products, or geographies does the moat protect?
A wide moat protects the company across multiple customer segments, product lines, or geographies. A narrow moat protects only a specific segment or geography. The difference is crucial: a company with a deep moat in one market but a narrow addressable market creates limited value. The same moat applied across multiple markets multiplies the value creation.
Network effects have tremendous width potential. Facebook's network moat protects not just social networking but also messaging, video, and advertising marketplaces built on top of the network. The moat does not narrow when the company expands into adjacent services; it often strengthens because the network value increases.
Brand advantage can be narrow or wide. Coca-Cola's brand is narrow in one sense—it primarily protects the cola category. Within cola, the brand is so strong that width is near-total. However, when Coca-Cola attempts to sell other beverages, the brand advantage narrower. The company's strength in cola does not automatically protect orange juice or coffee. This is why Coca-Cola has acquired many independent brands rather than relying solely on the Coca-Cola brand to dominate beverage retail.
Switching costs and ecosystem lock-in can be exceptionally wide. Microsoft's switching costs moat originally narrowed around personal computer office software. As the company extended into cloud services (Azure), gaming (Xbox), productivity software (Teams), and enterprise infrastructure, the ecosystem lock-in widened. Customers are more likely to stay with Microsoft across multiple product categories than to defect to best-of-breed alternatives because the integrated offering reduces friction. Apple has done the same with its ecosystem—iPhone, iPad, Mac, Watch, Services—where width is extensive because users do not want to forfeit the integration benefits.
Economies of scale can have limited width. A company that has achieved scale in manufacturing one product might have no cost advantage in manufacturing a different product. Scale moats are narrow in this sense. However, if the scale advantage is in distribution, marketing, or purchasing power, width can be broader. Amazon's scale advantage initially narrowed to e-commerce, but widened as the company leveraged AWS infrastructure, logistics networks, and advertising platforms across new markets.
The Moat Matrix: Combining Depth and Width
The most useful framework combines depth and width into a simple matrix:
| Wide Moat | Narrow Moat | |
|---|---|---|
| Deep | Maximum Value Creation | Concentrated Value |
| Shallow | Volume-Dependent Value | Minimal Competitive Advantage |
A company in the "deep and wide" quadrant is the ideal growth investment. Microsoft, Apple, Amazon, and Visa occupy this space. Their moats are deep (high ROIC spreads) and wide (protected across multiple markets and customer segments). Wealth creation compounds over decades because the company can reinvest excess returns at high rates of return across an expanding market.
A company in the "deep but narrow" quadrant creates significant value but faces concentration risk. If the moat exists only in a specific geography, product line, or customer segment, the total addressable market is limited. ASML, the Dutch semiconductor equipment manufacturer, possesses an extraordinarily deep moat in extreme ultraviolet (EUV) lithography—a moat so deep that it extracts monopoly-like returns. However, the moat is narrow because EUV is a specific segment of semiconductor manufacturing equipment. ASML creates tremendous value, but the width constraint limits the total wealth creation relative to companies with wider moats.
A company in the "shallow but wide" quadrant creates value primarily through volume and operational efficiency, not through pricing power. Walmart is the prototypical example. Its cost structure moat is shallow—competitors can also build efficient supply chains. Yet the moat is exceptionally wide because Walmart operates across all of retail. The company dominates through volume, turnover, and scale, not through the ability to charge premium prices. Growth investors should be cautious of this quadrant because value creation depends on continuous volume growth, and any market saturation threatens returns.
A company in the "shallow and narrow" quadrant is a value trap. It has neither deep competitive protection nor a wide addressable market. Growth investors should avoid this zone.
Width and Growth: The Critical Connection
For growth investors, width is the secret to transforming a good business into a compounding machine.
A company with a deep moat but narrow initial market can grow rapidly by expanding width—applying the same competitive advantage to new markets. Google dominated search advertising with a deep moat. As the company expanded into email, cloud services, mobile operating systems, and video, the width of the moat expanded, and the company's growth rate accelerated. The same moat protects the new markets, reducing the risk that growth comes at the expense of competitive advantage.
In contrast, a company that grows by entering markets where its moat does not apply is often taking on hidden risk. Growth appears strong in the financial statements, but the company is building no new competitive advantage. If the core moat erodes, the company has not built resilience through expansion.
This is why ecosystem expansion is so valuable. Apple's ecosystem expands the width of the moat with each new product category because each product increases the switching cost. A customer considering leaving the ecosystem loses not just their iPhone but their iPad, Mac, Watch, and Services subscription. The width expands faster than any single moat could grow independently.
Practical Framework for Assessment
When analyzing a potential investment, assess moat depth and width explicitly.
For depth: Calculate the company's ROIC and compare it to the cost of capital. A gap of 10 or more percentage points suggests a deep moat. A gap of 5 points or less suggests a shallow moat. Examine whether the ROIC spread has expanded, remained stable, or contracted over the past five years.
For width: Map the company's revenue across customer segments, product lines, and geographies. What percentage of revenue is protected by the core moat? What percentage is in adjacent markets where the moat applies but is less proven? What percentage is in new markets where the moat does not yet apply? A company where 70 percent of revenue is in the core moat has greater width than a company where only 30 percent is.
Companies that rank high on both dimensions—deep moat with high ROIC spreads, and wide application across multiple markets—are the growth investor's target. They combine the wealth-creation engine of high returns with the growth engine of expanding addressable markets. That combination is what transforms a good business into a multibagger.
Next
Depth and width combine to create moat strength, but how do you quantify that strength in terms of financial performance? The next article shows how return on invested capital reveals the true economic power of a moat.