We propose a formal concept of the power of voice in the context of a simple model where individuals form groups and trade in competitive markets. Individuals use outside options in two different ways. Actual outside options reflect the possibility to exit or to join other existing groups....

We We integrate individual power in groups into general equilibrium models. The relationship between group formation, resource allocation, and the power of specific individuals or particular sociological groups is investigated. We introduce, via an illustrative example, three appealing concepts...

We present a model of elections in which interest group donations allow candidates to shift policy positions. We show that if donations were prohibited, then a unique equilibrium regarding the platform choices of candidates would exist. Our game with financing of political campaigns exhibits two...