their practical relevance is still arguable. Another approach is to define ideal criteria that no electoral system passes perfectly, and then see how often or how close to passing various methods are over a large sample of simulated elections. This gives results which are practically relevant, but the method of generating the sample of simulated elections can still be arguably biased. A final approach is to create imprecisely defined criteria, and then assign a neutral body to evaluate each method according to these criteria. This approach can look at aspects of electoral systems which the other two approaches miss, but both the definitions of these criteria and the evaluations of the methods are still inevitably subjective. Arrow's theorem and the Gibbard–Satterthwaite theorem prove that no system using ranked voting can meet all such criteria simultaneously, while Gibbard's theorem proves the same for all deterministic voting methods. Instead of debating the importance of different criteria, another method is to simulate many elections with different electoral systems, and estimate the typical overall happiness of the population with the results, their vulnerability to strategic voting, their likelihood of electing the candidate closest to the average voter, etc. According to a 2006 survey of electoral system experts, their preferred electoral systems were in order of preference: Mixed member proportional Single transferable vote Open list proportional Alternative vote Closed list proportional Single member plurality Runoffs Mixed member majoritarian Single non-transferable vote Systems by elected body See also Comparison of electoral systems Election List of electoral systems by country Matrix vote Spoiler effect Psephology References External links ACE Electoral Knowledge Network The International IDEA Handbook of Electoral System Design IDEA Comparative politics Voting theory Public choice theory Psephology Social choice theory Elections