Other Market Forms

The other three market structure models can be defined in terms of the ways in which they deviate from the characteristics of P-Competition.

In a Monopoly there is just one seller of a good or service for which there is no close substitute.

In an oligopoly there are two or more, but only a few firms.

In Monopolistic Competition, the products are not homogenous but are "differentiated."

We don't have a standard model for "insufficient knowledge" but, at least in some cases, that seems to work similarly to "product differentiation."