The Coleman Power of the Collectivity to Act (CPCA) is a popular statistic that reflects the ability of a committee to pass a proposal. Applying the Shapley value to this measure, we derive a new power index that indicates each voter's contribution to the CPCA. This index is characterized by...

Experiments evaluate the fit of the Shapley-Shubik Power Index to a controlled human environment. Subjects with differing votes divide a fixed purse by majority rule in online chat rooms under supervision. Earnings serve as a measure of power. Chat rooms and processes for selecting subjects...