Cosmopolitan Networks in Commerce and Society 1660–1914

MARK CASSON
III. Basic Concepts of Network Theory
1. Connectivity and Configuration
The basic principles of network representation are set out in the
mathematical theory of graphs. 8 The defining feature of a network is
connection. A set of elements which are connected to each other form a
network. Every pair of elements belonging to a network is connected
up, either directly or indirectly. Indirect connections are effected
through other elements of the network.
From an economic and social perspective, there are four key
aspects of networks:
● size, as measured by the number of elements that belong to the
network;
● diversity, as measured by the number of different types of element
that belong to the network;
● the types of relationship that connect the members; and
● the configuration of the network, which describes the pattern in
which the different elements are connected up.
Economic historians have discussed relationships in considerable
detail, but have said surprisingly little about size and diversity, that
is, about the characteristics of the elements that are connected up.
Configuration has been studied even less by historians, and it is
therefore useful to begin by addressing this issue.
Considerable research has been carried out into the configurations
of physical networks, but remarkably little into the configuration
of social networks. 9 Conversely, far more research has been carried
out into the nature of relationships in social networks than in
8 See Norman L. Biggs, E. Keith Lloyd, and Robert Wilson, Graph Theory,
1736–1936 (Oxford, 1986); and Reinhard Diestel, Graph Theory (New York,
1997).
9 There are some notable exceptions, however. These include Patrick Direian
and Frans N. Stockman, Evolution of Social Networks (Amsterdam, 1997);
S. Wasserman and K. Faust, Social Network Analysis: Methods and Applications
(Cambridge, 1994); and Barry Wellman and S. D. Berkovitz (eds.) Social
Structures: A Network Approach (Cambridge, 1988).
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