What are the features of an imperfect or monopolistic market?

This is the market structure that is more commonly found in the real world. It borrows its characteristics heavily from both perfectly competitive markets and monopolies. It's characteristics are as follows:- A large number of firms that act independently- Product differentiation- Freedom of entry into, and exit out of, the market.- Non-price competition- Excess capacity (the difference between cost minimisation output and profit maximisation output)