Votes How Are Counted
1/27/09
Fairness Criteria (Restated)
IIA (independence from relative alternatives): the winning alternative should not depend on how many other alternatives are available. Monotonicity: voting rule does not put at a disadvantage an alternative obtaining more support among the voters.
Colomer, Table 3.1
What is the message behind these numbers? Who is the median voter/party in these cases?
How is it measured?
Single Winner Rules
Basic trade off: Effectiveness: capacity to produce outcomes Efficiency: social utility of those outcomes The more inclusive the rule:
the more efficient is the outcome, the less effectiveness in producing those outcomes
The more exclusive the rule:
the greater the effectiveness at producing outcomes outcomes more inefficient
Single Winner Rules
Unanimity: God's will and sovereign states
Efficiency--can be high but:
Depends on location of SQ Distribution of bargaining costs Agenda setting power
Ineffective
Immobility the danger Stability the reverse side
Monotonic Not IIA
Single Winner Rules
Majority: The will of the people?
More effective than unanimity Less efficient
More outcomes possible Greater instability
Can be nonmonotonic and non-IIA Examples:
Condorcet voting AV Run-offs
Single Winner Rules
Plurality: but...
Effective, (almost) always produces a winner (Effective) Highly inefficient in complex electorates Highly unstable--not IIA Non-monotonic (UK, US and LA pres.)
Multiple Winner Rules
Greater efficiency Two stages:
Multiwinner elections Multiparty government coalitions
Requires MMD
MMD with plurality
Cumulative vote Limited vote
SNTV
Bloc vote
Multiple Winner Rules
STV (AV with MMD)
Rank Votes over quota redistributed Votes for last candidate redistributed
PR w/ Party List
Higher M-->more parties, more proportionality and greater efficiency Quotas and divisor systems.
Can effect size of parties that benefit
Multiple Winner Rules
PR usually produces legislators with no majority party--> need coalition
Tend to form minimum connected winning coalitions In MCW coalitions, median voter always included Reproduced in cabinet (posts proportional to seats)
Median voter represented In plurality, winner takes all
Assessment
Is there a bottom-line preference, inherent in Colomer's discussion, over which type of electoral system to use? Counter arguments?
What about effectiveness under PR in terms of policy outcomes
Inclusive systems tend to be less effective Will depend on rule within cabinet
For some issues PR unworkable (categorical votes)