This book describes the progression and results of a decade-long program of experimental research on power in social exchange relations. Exchange theorists have traditionally excluded punishment and coercion from the scope of their analyses; but Molm examines whether exchange theory can be expanded to include reward and coercive power. Working within the framework of Emerson's power-dependence theory, but also drawing on the decision theory concepts of strategic action and loss aversion, Molm develops and tests a theory that emphasizes the interdependence of reward and coercive power. Her work shows that they are fundamentally different, not only in their effects on behavior, but also in the structural incentive to use power and the risks of power use. When exchanges are negotiated and secured by the 'shadow of the future,' rather than by binding agreements, dependence both encourages and constrains the use of coercion.