Experiments evaluate the fit of human behaviour to the Shapley-Shubik power index (SSPI), a formula of voter power … measured power. Chat rooms and processes for selecting subjects reduce or eliminate extraneous forces. Logrolling remains as … values. The SSPI can serve as a control for power imbedded in voting blocs, permitting fuller analysis of other factors that …

group of voters to pass a motion. A priori measures of voting power, such as the Shapley-Shubik index and the Banzhaf value …

vote independently of each other. Thus, we receive as an empirical result what the previous voting power literature assumed. …