A number of major U.S. corporations have expanded their activities over the years through conglomerate mergers. General Electric provides an excellent real world example. In the hypothetical world of Shady Valley, OmniComglomerate, Inc. offers an example of how a firm can expand through conglomerate mergers.

Beginning its existence as OmniMotors, it focused exclusively on the production of automobiles. However, it expanded and diversified through conglomerate mergers with such firms as The Acme Sundial Company, which manufactured sundials; Tasty Cola Drinks, which produced soft drinks; Bank of the World, which offered banking services; and Mobility-Plus, which provided wireless telephone services.

Conglomerate mergers are considered relatively harmless when it comes to inefficiencies that result from market control. Because a conglomerate merger is between two firms in different industries, the degree of competition within EACH industry is largely unaffected.

Suppose, for example, that The Master Foot Company, a leading manufacturer of athletic shoes, merges with Juice-up, a soft drink firm. The resulting company (call it Juicy Foot) is faced with the same competition in each of its two markets after the merger as the individual firms were before the merger. The Master Foot division of Juicy Foot must still compete with its arch rival OmniRun. And the Juice-Up division of Juicy Foot must still compete with OmniCola, King Caffeine, Frosty Grape, and others in the soft drink market.

While conglomerate mergers tend to be relatively harmless, they can set the stage for problems. If several different markets are dominated by divisions owned by two large conglomerates, the potential for collusion is greater. Suppose, for example, that OmniConglomerate, Inc. controls OmniRun in the athletic shoe market, OmniCola in the soft drink market, OmniCell in the wireless telephone market, and OmniMotors in the automobile market. Also suppose that another conglomerate, Juicy Foot, controls Digital Distance in the wireless telephone, market and Mega Mobile in the automobile market, in addition to Juice-Up in the soft drink market and Master Foot in the athletic shoe market.