Structural Holes

A structural hole in a social network exists between two of a focal actor's contacts if they are nonredundant. Contacts are redundant due either to cohesion, where they have a direct connection to one another, or through structural equivalence, where they have no direct connection but are indirectly connected to the same other actors. Actors who are able to bridge structural holes are also known as brokers or liaisons.

The theory of structural holes assumes that being a liaison is beneficial to the focal actor. When contacts are neither directly nor indirectly connected to one another, then it follows that the structural hole between them has two features: (1) the two contacts provide access to structurally separate pools of information, and (2) the focal actor serves as the unique broker between the contacts, rendering him tertius gaudens (the third who benefits). That is, a structural hole confers a liaison with greater ability to broker indirect connections between other contacts and control the flow of information between them. By providing information and brokerage benefits, structural holes constitute a form of social capital.

The ability to broker indirect connections between other contacts and control the flow of information is a form of social capital.

Research on structural holes has provided empirical support for such structural advantages. Structural advantages in this work are typically measured using the [Page 828]constraint measure, which mathematically captures the degree of redundancy in the ego-network of an actor. Employees and managers with less constraint in their personal networks show better performance evaluations, faster promotions, higher compensation, and better ideas. Organizations in positions of brokerage are perceived as more influential and tend to have higher profit margins. Structural holes have also been found to be associated with more success in organized crime, and the phenomenon has also been identified in early Renaissance politics; for example, politically powerful Medici occupied a central position in the 15th-century network of elite Italian families.