A natural monopoly exists when increasing returns to scale provide a large cost advantage to a single
firm that produces all of an industry’s output.
An example could be gas companies which supply gas to entire cities. The number of gas companies is
not greater than 1 owing to increasing returns to scale. When the gas industry was just starting up,
many companies competed for local customers. But this competition didn’t last long as local gas supply
soon became a monopoly in almost every city. Firms with larger volumes of sales had an advantage:
they were able to spread the fixed costs over a larger volume and therefore had lower average total cost
than smaller firms. The phenomenon that average total cost falls as output increases is called increasing
returns to scale. This leads to firms growing larger and establishing a monopoly. In an industry
characterized by increasing returns to scale, larger companies are more profitable and drive out smaller
ones. This also prevents new companies from entering the competition. So, increasing returns to scale
can both give rise to and sustain a monopoly.
A natural monopolist’s Average total cost curve (ATC) declines over the output levels at which price is
greater than or equal to average total cost. The natural monopolist has increasing returns to scale over
the entire range of output for which any firms would want to remain in the industry- the range of output
at which the firm would at least break even in the long run. The source of this condition is large fixed
costs: when large fixed costs are required to operate, a given quantity of output is produced at lower
average total cost by one large firm than by two or more smaller firms.
Local utility companies are the most common example of natural monopolies.
(Figure 13-3)
• Technological superiority:
A firm that maintains a constant technological advantage over potential competitors can establish itself
as a monopolist. For example, Intel was able to sustain a technological advantage from the 1970s to
1990s in the manufacture of microprocessors. But technological superiority is typically not a barrier
because over the long term, competitors will invest in upgrading their technology to match that of the
technology leader.
Technological superiority, however, is not a guarantee of success because of network externalities.
• Network externality:
A network externality exists when the value of a good or service to an individual is greater when many
other people use the good or service as well. Network externalities are very prevalent in technology and
communications sectors of the economy. An example could be the Facebook. The value of Facebook
page increases if more people use it.
When a network externality exists, the firm with the largest network of customers using its product has
an advantage in attracting new customers, one that may allow it to become a monopolist. It can charge
a higher price and so earn higher profits.