Ronald S. Burt 
Structural Holes [PDF ebook] 
The Social Structure of Competition

Ronald Burt describes the social structural theory of competition that has developed through the last two decades. The contrast between perfect competition and monopoly is replaced with a network model of competition. The basic element in this account is the structural hole: a gap between two individuals with complementary resources or information. When the two are connected through a third individual as entrepreneur, the gap is filled, creating important advantages for the entrepreneur. Competitive advantage is a matter of access to structural holes in relation to market transactions.