Table 1 Measures of centrality [24]

Degree: the more ties (direct connections) an actor has, the more power they (may) have. Actors who have more ties have greater opportunities because they have more choices.

In-degree: the number of ties that lead into the actor directly from others, that is, the number of respondents who identified a particular actor as influential.

Out-degree: the number of ties that lead out of the actor directly to others, that is, the number of others identified by an individual actor as influential.

Closeness: If an actor is able to reach other actors at shorter path lengths, particularly decision-makers they will have greater influence. This position means power can be exerted by direct bargaining and exchange. Actors who are able to reach other actors at shorter path lengths have greater power and capacity to influence.

Betweenness: If an actor lies between other actors, that is, they act as a ‘broker’ that others must go through to reach a different group of people; they are in a position of power.