A number of factors coalesced to make larger and larger firms more economical. The development of new production processes, such as assembly line, means that jobs could be specialized and more work could be accomplished. New technologies and sources of power became readily available. Demographic factors began to favor concentration of production in urban areas. These and other social and political forces require larger amounts of capital, well beyond the scope of most individual owner-manager-employee.

p. 5 - Strategic Management: A Stakeholder Approach, 2007