We discuss two inter-related puzzling features of the literature on a priori voting power. First, the mathematical model used in virtually all this literature does not recognize abstention as an option distinct from both a 'yes' and a 'no' vote. Second, reallife decision rules of voting bodies -...

We explain the issue of the decision rule of the EU’s Council of Ministers. We outline, in as non-technical fashion as we can, the mathematical theory (due to L S Penrose) that addresses this sort of issue. We assess the decision rule prescribed in the Nice Treaty as well as that included in...

These are critical remarks on Holler and Widgrén (1999) and in particular on Holler's Public Good Index. The central idea is a distinction between two underlying pre-formal notions of a priori voting power: power as influence over the outcome, and power as expected relative share in a payoff.