Power is the ability to make things happen. A manager is more likely to be effective if she can tap multiple sources of power. These sources are:
The power associated with a specific position. Thus, the position of chief operating officer confers a substantial amount of power on the holder of that position.
The power to reward employees. When a person is able to hand out pay raises or other benefits, this tends to confer a certain amount of power. For example, the human resources director tends to have more power than the title itself would imply, because this person advises management about pay raises and promotions.
The power associated with being an expert. When a person has a highly specialized skill, people tend to follow her recommendations. This type of power can be distributed throughout an organization. For example, an information technology expert will have substantial power over the choice of software that a business purchases.
The power associated with personal characteristics. People who are admired have a certain amount of power to influence others. For example, an unusually empathetic manager who has earned a solid reputation for fair dealings with her subordinates will likely gain power through their loyalty to her.
The power of networking. When a person is deeply embedded in a network of interpersonal connections within (and outside of) a business, this position can confer a significant amount of power. Networkers can strongly influence the opinions of others, even when they are located in odd corners of the official corporate hierarchy.
Truly powerful managers probably combine several of these sources of power. The most likely combination is the power associated with having a specific position and the power derived from being a strong networker. Weaker managers only rely on their ability to reward or coerce employees, which tends to drive the best performers out of a business in short order.