Also adversely affected by the monopoly are those sellers who might have earned a livelihood in that market, but who are compelled by the policy to seek to earn a living in some less satisfactory manner. The legally excluded sellers may even attempt to create black-market competitive businesses, catering to buyers who wish to avoid monopoly prices; as they pursue their mutual self-interest, the illegal sellers and buyers are thus placed in an antagonistic relationship with the government. Periodically, for instance, private enterprises have challenged the first-class postal monopoly, reaping considerable profits and bringing low-cost, efficient service to their customers—until they have been shut down by federal authorities.

Because legal monopolies have adverse effects on so many and bring only short-term profits even to the monopolists, it may be wondered why they receive some widespread acceptance. First, those who initially profit from the monopoly policy tend to acquire exceptional political power, under circumstances that will be further explored in Section 5. The owners, management, and labor force of the monopoly, as well as regulators and bureaucrats within the government who are charged with monitoring its operations and proscribing competition, perceive themselves (rightly or wrongly) as beneficiaries of the policy and seek vigorously to ensure its continuation.