A firm is an economic entity engaged in business. Economic theory assumes that the firm, like the consumer, maximises its self-interest. This self interest is however the product of the interplay of market structure, business organisation, and chosen or required objective. So, for instance, some firms might choose to profit-maximise, some to profit satisfy, some to revenue maximise, and some to sales-maximise, or even engage in loss-leading predatory behaviours. Oligopoly firms might take their cue from other firms, and find that price-maximisation is only really possible if they can join a cartel; imperfectly competitive firms might sustain a loss in the short run, covering their variable costs and making a contribution to fixed ones, if they think that this will lead to ultimate survival in a temporarily tough market. These decisions often relate to the nature of the firms. A sole trader’s objective, for instance, may include the freedom and control that working for on...