One constraint on the growth of any firm is entrepreneurs have a limited span of control (Coase 1937; Williamson 1967, Lucas 1978; Oi 1983a, 1983b). A span of control is the number of subordinates that an individual supervisor has to control and lead either directly or through a hierarchical managerial chain (Fox 2009).
There are only so many tasks that even the most able entrepreneurs can carry out in one day. Over-stretched spans of control motivate entrepreneurs to hire professional managers and delegate to them a wide range of decision-making rights over the firms they own (Williamson 1975; Foss, Foss and Klein 2008).
Entrepreneurs and the professional managers they hired to assist them must divide their respective time between monitoring employees, identifying new business opportunities, forecasting buyer demand and running the other aspects of their business (Lucas, 1978; Oi 1983, 1983b, 1988; Foss, Foss, and Klein 2008). The larger is the firm, the more employees there are for the entrepreneur to direct, monitor and reward. These costs of directing and monitoring employees will increase with the size of the firm and larger firms will encounter information problems not present in smaller firms (Alchian and Demsetz 1972; Stigler 1962).
The cost of entrepreneurial time spent monitoring employees will increase with the size of the firm (Lucas 1978; Oi 1983b). The time of the more talented entrepreneurs is more valuable because they had the superior managerial skills and entrepreneurial alertness to make their firms large in the first place and remain deft enough to survive in competition. Time spent on the supervision of employees is time that is spent away from other uses of the talents that got these more able entrepreneurs to the top and keeps them there (Williamson 1967; Lucas 1978; Oi 1983b, 1988, 1990; Idson and Oi 1999; Black et al 1999).
Firms in the same industry tend to exhibit systematic differences in their organization of production and the structure of their workforces because entrepreneurial ability is the specific and scarce production input that limits the size of a firm (Lucas, 1978; Oi 1983b). The less able entrepreneurs tend to run the smaller firms while the more able entrepreneurs tend to lead both the currently large firms and the smaller firms that are growing at the expense of market rivals (Lucas 1978, Oi 1983b; Stigler 1958; Alchian 1950).