| Characteristic | Perfect Competition | Monopolistic Competition | Oligopoly | Monopoly |
| Number of firms | Many | Many | Few | One |
| Product differentiation | No | Yes | Yes or No | No |
| Control over price | None | Within narrow limits | Varies, depending on the degree of mutual interdependence and collusion | Considerable, limited by consumers’ willingness to pay |
| Barriers to entry | None | Few if any | Considerable | Prohibitive |
| Example | Agriculture | Restaurants | Airlines | Utilities |