Several months ago somebody on the list (can't remember who) recommended a book on the measurement of voting power (can't remember the exact title either). They cover a wide range of voting systems, including those where some voters have unequal weight (e.g. shareholders, electoral college), those that require a supermajority (e.g. Constitutional amendments in Congress), and those where some voters have veto powers but not dictatorial powers (e.g. UN Security Council).
They generally look at an electorate, or set of voters, and ask which subsets of that electorate are sufficient to enact a resolution. Suppose that two winning subsets are called S1 and S2. If there exist winning subsets S1 and S2 such that the intersection of S1 and S2 is empty then they call it an "Improper Voting Game". If all pairs of winning subsets have a non-empty intersection they call it a "Proper Voting Game". They point out the pejorative-sounding "Improper" label is given because in such a system a resolution could be enacted by a group of voters, and then immediately after a counter-resolution could be enacted by the opposition. This could go on and on, hardly a stable system. A system in which a minority can enact a policy fits the "Improper Voting Game" definition. Hence, one could say that the Majority Criterion is important in the interests of stability. Alex ---- For more information about this list (subscribe, unsubscribe, FAQ, etc), please see http://www.eskimo.com/~robla/em
