are guided by prices and quality as illustrated by vegetable markets where a buyer is free to switch sellers in an exchange. The need for a revised theory of the firm was emphasized by empirical studies by Adolf Berle and Gardiner Means, who made it clear that ownership of a typical American corporation is spread over a wide number of shareholders, leaving control in the hands of managers who own very little equity themselves. R. L. Hall and Charles J. Hitch found that executives made decisions by rule of thumb rather than in the marginalist way. Transaction cost theory According to Ronald Coase's essay The Nature of the Firm, people begin to organise their production in firms when the transaction cost of coordinating production through the market exchange, given imperfect information, is greater than within the firm. Ronald Coase set out his transaction cost theory of the firm in 1937, making it one of the first (neo-classical) attempts to define the firm theoretically in relation to the market. One aspect of its 'neoclassicism' lies in presenting an explanation of the firm consistent with constant returns to scale, rather than relying on increasing returns to scale. Another is in defining a firm in a manner which is both realistic and compatible with the idea of substitution at the margin, so instruments of conventional economic analysis apply. He notes that a firm's interactions with the market may not be under its control (for instance because of sales taxes), but its internal allocation of resources are: “Within a firm, … market transactions are eliminated and in place of the complicated market structure with exchange transactions is substituted the entrepreneur … who directs production.” He asks why alternative methods of production (such as the price mechanism and economic planning), could not either achieve all production, so that either firms use internal prices for all their production, or one big firm runs the entire economy. Coase begins from the standpoint that markets could in theory carry out all production and that what needs to be explained is the existence of the firm, with its "distinguishing mark … [of] the supersession of the price mechanism." Coase identifies some reasons why firms might arise, and dismisses each as unimportant: if some people prefer to work under the direction and are prepared to pay for the privilege (but this is unlikely); if some people prefer to direct others