Measurement of power, probabilities, and alternative models of man

Starting from Max Weber's definitions of power we discuss the meaning of his concept Chance and its relationships to the probabilistic notions that play a central role in definitions of indices of measuring voting power. Using Martin Hollis's distinction between two models of man plastic and autonomous we argue that the common measures of voting power when interpreted in terms of probabilities seem to be in better conformity with the model of plastic man than with the model of autonomous man. The paper elaborates on the probability interpretation with applications to the modelling of power measures with a priori unions and to the concept of "real voting power" based on relative frequencies of historical events. Power as potential which in our view is what Weber very likely meant remains an elusive concept, but one that should be amenable to game-theoretic analysis.