Penrose and the Indifferent Crowd

Today Lionel Penrose is recognised as the co-author of one of the two leading indices of power in voting legislatures – a field of study that game theory in general, and cooperative game theory in particular, has been reclaiming from sociology and political science since the 1950s. The main claim of this paper is that Penrose developed his index so as to tackle questions that go vastly beyond the narrow domain of voting; namely, acute social issues during the Cold War such as the outburst and propagation of panics, the ideological susceptibility of populations, the escalation of military conflict and the successful installation of authoritarian regimes. Furthermore, by revisiting the history of the Penrose power index, the paper re-evaluates some of its key underlying assumptions: assumptions that have been heavily – and unfairly, as the paper argues – criticised over the last decade.