Diagram of Porter's 5 Forces
	SUPPLIER POWER Supplier concentration Importance of volume to supplier Differentiation of inputs Impact of inputs on cost or differentiation Switching costs of firms in the industry Presence of substitute inputs Threat of forward integration Cost relative to total purchases in industry
BARRIERS TO ENTRY Absolute cost advantages Proprietary learning curve Access to inputs Government policy Economies of scale Capital requirements Brand identity Switching costs Access to distribution Expected retaliation Proprietary products		THREAT OF SUBSTITUTES Switching costs Buyer inclination to substitute Price-performance trade-off of substitutes
	BUYER POWER Bargaining leverage Buyer volume Buyer information Brand identity Price sensitivity Threat of backward integration Product differentiation Buyer concentration vs. industry Substitutes available Buyers' incentives	DEGREE OF RIVALRY Exit barriers Industry concentration Fixed costs/Value added Industry growth -Intermittent overcapacity Product differences Switching costs Brand identity Diversity of rivals Corporate stakes

I. Rivalry

In the traditional economic model, competition among rival firms drives profits to zero. But competition is not perfect and firms are not unsophisticated passive price takers. Rather, firms strive for a competitive advantage over their rivals. The intensity of rivalry among firms varies across industries, and strategic analysts are interested in these differences.

Economists measure rivalry by indicators of  industry concentration. The Concentration Ratio (CR) is one such measure. The Bureau of Census periodically reports the CR for major Standard Industrial Classifications (SIC's). The CR indicates the percent of market share held by the four largest firms (CR's for the largest 8, 25, and 50 firms in an industry also are available). A high concentration ratio indicates that a high concentration of market share is held by the largest firms - the industry is concentrated. With only a few firms holding a large market share, the competitive landscape is less competitive (closer to a monopoly). A low concentration ratio indicates that the industry is characterized by many rivals, none of which has a significant market share. These fragmented markets are said to be competitive. The concentration ratio is not the only available measure; the trend is to define industries in terms that convey more information than distribution of market share.

If rivalry among firms in an industry is low, the industry is considered to be disciplined. This discipline may result from the industry's history of competition, the role of a leading firm, or informal compliance with a generally understood code of conduct. Explicit collusion generally is illegal and not an option; in low-rivalry industries competitive moves must be constrained informally. However, a maverick firm seeking a competitive advantage can displace the otherwise disciplined market.

When a rival acts in a way that elicits a counter-response by other firms, rivalry intensifies. The intensity of rivalry commonly is referred to as being cutthroat, intense, moderate, or weak, based on the firms' aggressiveness in attempting to gain an advantage.

In pursuing an advantage over its rivals, a firm can choose from several competitive moves:

• Changing prices - raising or lowering prices to gain a temporary advantage.

• Improving product differentiation - improving features, implementing innovations in the manufacturing process and in the product itself.

• Creatively using channels of distribution - using vertical integration or using a distribution channel that is novel to the industry. For example, with high-end jewellery stores reluctant to carry its watches, Timex moved into drugstores and other non-traditional outlets and cornered the low to mid-price watch market.

• Exploiting relationships with suppliers - for example, from the 1950's to the 1970's Sears, Roebuck and Co. dominated the retail household appliance market. Sears set high quality standards and required suppliers to meet its demands for product specifications and price.

The intensity of rivalry is influenced by the following industry characteristics:

In Porter's model, substitute products refer to products in other industries. To the economist, a threat of substitutes exists when a product's demand is affected by the price change of a substitute product. A product's price elasticity is affected by substitute products - as more substitutes become available, the demand becomes more elastic since customers have more alternatives. A close substitute product constrains the ability of firms in an industry to raise prices.

The competition engendered by a Threat of Substitute comes from products outside the industry. The price of aluminium beverage cans is constrained by the price of glass bottles, steel cans, and plastic containers. These containers are substitutes, yet they are not rivals in the aluminium can industry. To the manufacturer of automobile tires, tire retreads are a substitute. Today, new tires are not so expensive that car owners give much consideration to retreading old tires. But in the trucking industry new tires are expensive and tires must be replaced often. In the truck tire market, retreading remains a viable substitute industry. In the disposable diaper industry, cloth diapers are a substitute and their prices constrain the price of disposables.

While the treat of substitutes typically impacts an industry through price competition, there can be other concerns in assessing the threat of substitutes. Consider the substitutability of different types of TV transmission: local station transmission to home TV antennas via the airways versus transmission via cable, satellite, and telephone lines. The new technologies available and the changing structure of the entertainment media are contributing to competition among these substitute means of connecting the home to entertainment. Except in remote areas it is unlikely that cable TV could compete with free TV from an aerial without the greater diversity of entertainment that it affords the customer.

The power of buyers is the impact that customers have on a producing industry. In general, when buyer power is strong, the relationship to the producing industry is near to what an economist terms a monopsony - a market in which there are many suppliers and one buyer. Under such market conditions, the buyer sets the price. In reality few pure monopsonies exist, but frequently there is some asymmetry between a producing industry and buyers. The following tables outline some factors that determine buyer power.

A producing industry requires raw materials - labour, components, and other supplies. This requirement leads to buyer-supplier relationships between the industry and the firms that provide it the raw materials used to create products. Suppliers, if powerful, can exert an influence on the producing industry, such as selling raw materials at a high price to capture some of the industry's profits. The following tables outline some factors that determine supplier power.
 
 

Suppliers are Powerful if:	Example
Credible forward integration threat by suppliers	Baxter International, manufacturer of hospital supplies, acquired American Hospital Supply, a distributor
Suppliers concentrated	Drug industry's relationship to hospitals
Significant cost to switch suppliers	Microsoft's relationship with PC manufacturers
Customers Powerful	Boycott of grocery stores selling non-union picked grapes
Suppliers are Weak if:	Example
Many competitive suppliers - product is standardized	Tire industry relationship to automobile manufacturers
Purchase commodity products	Grocery store brand label products
Credible backward integration threat by purchasers	Timber producers relationship to paper companies
Concentrated purchasers	Garment industry relationship to major department stores
Customers Weak	Travel agents' relationship to airlines

It is not only incumbent rivals that pose a threat to firms in an industry; the possibility that new firms may enter the industry also affects competition. In theory, any firm should be able to enter and exit a market, and if free entry and exit exists, then profits always should be nominal. In reality, however, industries possess characteristics that protect the high profit levels of firms in the market and inhibit additional rivals from entering the market. These are barriers to entry.

Barriers to entry are more than the normal equilibrium adjustments that markets typically make. For example, when industry profits increase, we would expect additional firms to enter the market to take advantage of the high profit levels, over time driving down profits for all firms in the industry. When profits decrease, we would expect some firms to exit the market thus restoring a market equilibrium. Falling prices, or the expectation that future prices will fall, deters rivals from entering a market. Firms also may be reluctant to enter markets that are extremely uncertain, especially if entering involves expensive start-up costs. These are normal accommodations to market conditions. But if firms individually (collective action would be illegal collusion) keep prices artificially low as a strategy to prevent potential entrants from entering the market, such entry-deterring pricing establishes a barrier.

Barriers to entry are unique industry characteristics that define the industry. Barriers reduce the rate of entry of new firms, thus maintaining a level of profits for those already in the industry. From a strategic perspective, barriers can be created or exploited to enhance a firm's competitive advantage. Barriers to entry arise from several sources:

1. Government creates barriers. Although the principal role of the government in a market is to preserve competition through anti-trust actions, government also restricts competition through the granting of monopolies and through regulation. Industries such as utilities are considered natural monopolies because it has been more efficient to have one electric company provide power to a locality than to permit many electric companies to compete in a local market. To restrain utilities from exploiting this advantage, government permits a monopoly, but regulates the industry. Illustrative of this kind of barrier to entry is the local cable company. The franchise to a cable provider may be granted by competitive bidding, but once the franchise is awarded by a community a monopoly is created. Local governments were not effective in monitoring price gouging by cable operators, so the federal government has enacted legislation to review and restrict prices.

The regulatory authority of the government in restricting competition is historically evident in the banking industry. Until the 1970's, the markets that banks could enter were limited by state governments. As a result, most banks were local commercial and retail banking facilities. Banks competed through strategies that emphasized simple marketing devices such as awarding toasters to new customers for opening a checking account. When banks were deregulated, banks were permitted to cross state boundaries and expand their markets. Deregulation of banks intensified rivalry and created uncertainty for banks as they attempted to maintain market share. In the late 1970's, the strategy of banks shifted from simple marketing tactics to mergers and geographic expansion as rivals attempted to expand markets.

2. Patents and proprietary knowledge serve to restrict entry into an industry. Ideas and knowledge that provide competitive advantages are treated as private property when patented, preventing others from using the knowledge and thus creating a barrier to entry. Edwin Land introduced the Polaroid camera in 1947 and held a monopoly in the instant photography industry. In 1975, Kodak attempted to enter the instant camera market and sold a comparable camera. Polaroid sued for patent infringement and won, keeping Kodak out of the instant camera industry.

3. Asset specificity inhibits entry into an industry. Asset specificity is the extent to which the firm's assets can be utilized to produce a different product. When an industry requires highly specialized technology or plants and equipment, potential entrants are reluctant to commit to acquiring specialized assets that cannot be sold or converted into other uses if the venture fails. Asset specificity provides a barrier to entry for two reasons: First, when firms already hold specialized assets they fiercely resist efforts by others from taking their market share. New entrants can anticipate aggressive rivalry. For example, Kodak had much capital invested in its photographic equipment business and aggressively resisted efforts by Fuji to intrude in its market. These assets are both large and industry specific. The second reason is that potential entrants are reluctant to make investments in highly specialized assets.

4. Organizational (Internal) Economies of Scale. The most cost efficient level of production is termed Minimum Efficient Scale (MES). This is the point at which unit costs for production are at minimum - i.e., the most cost efficient level of production. If MES for firms in an industry is known, then we can determine the amount of market share necessary for low cost entry or cost parity with rivals. For example, in long distance communications roughly 10% of the market is necessary for MES. If sales for a long distance operator fail to reach 10% of the market, the firm is not competitive.

The existence of such an economy of scale creates a barrier to entry. The greater the difference between industry MES and entry unit costs, the greater the barrier to entry. So industries with high MES deter entry of small, start-up businesses. To operate at less than MES there must be a consideration that permits the firm to sell at a premium price - such as product differentiation or local monopoly.

Barriers to exit work similarly to barriers to entry. Exit barriers limit the ability of a firm to leave the market and can exacerbate rivalry - unable to leave the industry, a firm must compete. Some of an industry's entry and exit barriers can be summarized as follows:

Our descriptive and analytic models of industry tend to examine the industry at a given state. The nature and fascination of business is that it is not static. While we are prone to generalize, for example, list GM, Ford, and Chrysler as the "Big 3" and assume their dominance, we also have seen the automobile industry change. Currently, the entertainment and communications industries are in flux. Phone companies, computer firms, and entertainment are merging and forming strategic alliances that re-map the information terrain. Schumpeter and, more recently, Porter have attempted to move the understanding of industry competition from a static economic or industry organization model to an emphasis on the interdependence of forces as dynamic, or punctuated equilibrium, as Porter terms it.

In Schumpeter's and Porter's view the dynamism of markets is driven by innovation. We can envision these forces at work as we examine the following changes: