A price searcher refers to an aggressive shopper. The following is true in equilibrium for all firms selling goods and services in a market economy. Profit is equal to zero. At equilibrium output the firm is producing as much as it is capable of producing. Externalities lead to a market solution in which resources are not allocated according to their best use.
Externalities often exist when property rights are poorly or incompletely defined.
Externalities result in a quantity produced that is not the optimal quantity. Cartels can be successful or unsuccessful. For example, if a cartel breaks apart due to the actions of its members it is unsuccessful. Firms in the industry should be producing a very similar product. There should be a large number of firms in the industry.