List some restrictions on the mobility of resources that might help a firm retain monopoly power.

The restrictions that a monopoly firm can impose in order to retain its power, are:

1. Control over physical resources: When a firm establishes control over the resource, whether it is in the form of inputs required to produce the final product sold by the monopoly or is the final product in itself, the firm can maintain its monopoly power. For example, oil.

2. Legal or state-imposed barriers to entry: In this case, the legal system/ the government imposes certain barriers which prevent the mobility of resources, thereby limiting the possibility of competition. The most common examples are government regulations regarding singular/ few suppliers of electricity or water. The rationale behind most legal monopolies or state-imposed barriers is the economies of scale.

3. Technological resource: The products created out of research and development (R&D) tend to be replicated without the investment of R&D, and therefore copyright, patents, trademarks are used to create intellectual property. The limited use of intellectual property also restricts resource utilization allowing for the continuation of monopoly.