From Power for All, by Julie Battilana and Tiziana Casciaro:
There are two common threads across these definitions [of power across the social sciences]. The first is that the authors view power as the ability of a person or a group of people to produce an effect on others–that is, to influence their behaviors. This influence can be exercised in different ways, which has led social scientist to distinguish between different forms of power. As summarized by the sociologist Manuel Castells, “Power is exercised by means of coercion (the monopoly on violence, legitimate or not, by the state) and/or by the construction of meaning in people’s minds through mechanisms of cultural production and distribution.” Therefore, two broad categories underpin the types of power identified in the literature. The first category encompasses persuasion-based types of powre, such as expert power that stems from trusting someone’s know-how, referent power that stems from admiration for or identification with someone, or power stemming from control over cultural norms. The other category comprises coercion-based types of power that include the use of force (be it physically violent or not) and authority (or “legitimate power”) to influence people’s behaviors. Building on this large and rich body of work, we define power as the ability to influence another person or group’s behavior, be it through persuasion or coercion.
The second common thread is that thye all, implicitly or explicitly, posit that power is a function of one actor’s dependence on another. Social exchange theory articulates this view clearly in the seminal model of power-dependence relations developed by sociologist Richard Emerson. In this view, power is the inverse of dependence. The power of Actor A over Actor B is the extent to which Actor B is dependent on Actor A. The dependence oof Actor B on Actor A is “directly proportional to B’s motivational investment in goals mediated by A and inversely proportional to the availability of those goals to B outside of the A-B relation.” The fundamentals of power that we present in this book are derived from this conceptualization of powre. They posit that the power of Actor A over Actor B depends on the extent to which A controls access over resoures that B values and that, in turn, the power of Actor B over Actor A depends on the extent to which B controls access over resources that A values. It follows from the fundamentals of power that power is always relational and that it is not a zero-sum game. The power relationship between A and B may be balanced if A and B are mutually dependent and they each value the resources that the other party has access to. It is imbalanced if one of the parties needs the resources that the other party can provide more.
Importantly the resources that each of the parties value may be psychological as well as material…
Cultural norms shape what is valued in a given context, while the distribution of resources favors some people and organizations and disadvantages others…p. 200-201 (Appendix); emphasis added.
And strategies for shifting power: