I'm not sure it's sufficiently studied, but there is some study of power relationships in economics, mostly in areas of economics that argue over the effects of entity sizes and coordination. The theory of both antitrust law and labor law is mostly based on arguments over power imbalances, e.g. whether cartels exercise coercive power that distorts markets, and what power relationships are involved when an individual negotiates with a large corporation (or on the other side, when a large union negotiates with a smaller employer).