Outside the firm, price movements direct production, which is co-ordinated through a series of exchange transactions on the market. Within a firm, these market transactions are eliminated and in place of the complicated market structure with exchange transactions is substituted the entrepreneur-co-ordinator, who directs production.
Ronald CoaseWe must first note that economic factors are taken into account in a world in which ignorance, prejudice, and mental confusion, encouraged rather than dispelled by the political organization, exert a strong influence on policy making.
Ronald CoaseA firm, therefore, consists of the system of relationships which comes into existence when the direction of resources is dependent on an entrepreneur... As a firm gets larger, there may be decreasing returns to the entrepreneur function, that is, the costs of organising additional transactions within the firm may rise.
Ronald Coase