Group Details Private


  • RE: What type of party system are STAR and approval voting likely to promote, are there papers on this?

    @kaptain5 I don’t think there are any good empirical and longitudinal case studies on emergent behaviors in government like party formation or coalitions as a consequence of either voting method. Approval voting and STAR aren’t used in many national elections as far as I am aware. Studies that suggest any patterns of emergent behaviors of that type related to approval voting or STAR voting would likely be simulations via agent-based modeling.

    Nevertheless, what follows is ChatGPT4o’s rough assessment based on my own hopefully somewhat informed questions, the answers to which should be fact-checked, and may give you some leads. In general, the evidence seems to suggest that approval voting would produce more diversified parties with broader coalitions, which is more aligned with a model of “consensus” versus “majoritarian” democracy, but this should be cautiously considered since the empirical, longitudinal and reproducible evidence is lacking (although the evidence we do have also aligns with intuition and at least semi-logical reasoning to the same conclusion—that either method would surely be no worse than and likely significantly superior to what we have now):

    1. “ Can you organize an assessment about nations that use approval voting and how that affects the number of parties and party coalition formations in government?”

    “ Sure, here's an organized assessment on the impact of approval voting on the number of parties and party coalition formations in government:


    Approval voting is a voting system in which voters can select ("approve") any number of candidates, and the candidate with the most approvals wins. This system contrasts with traditional plurality voting, where voters select only one candidate, and the candidate with the most votes wins. This assessment explores how approval voting affects the number of political parties and the formation of party coalitions in government.

    Nations Using Approval Voting

    Approval voting is relatively uncommon in national elections but has been adopted in various forms at local and organizational levels. The primary examples of approval voting in practice include:

    1. Frenchtown, Montana, USA: Used for city council elections.
    2. St. Louis, Missouri, USA: Adopted for municipal elections in 2020.
    3. Fargo, North Dakota, USA: Adopted for local elections in 2018.

    Impact on Number of Parties

    Theoretical Perspectives

    • Duverger's Law: Suggests that plurality voting systems tend to favor a two-party system, while proportional representation systems favor multi-party systems.
    • Approval Voting Hypothesis: Approval voting, by allowing voters to support multiple candidates, reduces the "wasted vote" phenomenon and may encourage the growth of smaller parties.

    Empirical Evidence

    • Local Elections in the USA: In places like St. Louis and Fargo, where approval voting has been implemented, there is some evidence of increased diversity in candidates and more competitive races. However, comprehensive longitudinal data is limited due to the recent adoption of the system.
    • Organizational Elections: In organizations using approval voting, there tends to be a wider range of candidates elected, suggesting a more representative outcome.

    Impact on Party Coalition Formations

    Coalition Formation Theory

    • Plurality Systems: Often lead to single-party governments or minimal winning coalitions.
    • Proportional Representation: Encourages broader coalitions and multi-party governments.
    • Approval Voting: Potentially encourages coalition building even in non-proportional systems, as candidates and parties might seek broader support across the electorate.

    Case Studies

    • Fargo, North Dakota: Initial observations suggest that approval voting has led to a more collaborative and less polarized city commission, although it's too early to draw definitive conclusions about coalition behavior.
    • St. Louis, Missouri: Early implementation results indicate that candidates are motivated to appeal to a broader base, potentially leading to more moderate and coalition-oriented governance.

    Some citations to investigate:

    Comparative Analysis

    Approval Voting vs. Plurality Voting

    • Number of Parties: Approval voting has the potential to increase the number of viable political parties by reducing the strategic disadvantage of voting for smaller parties.
    • Coalition Formation: Encourages broader, more inclusive coalitions by rewarding candidates who can gain approval from a wider segment of the electorate.

    Approval Voting vs. Proportional Representation

    • Number of Parties: Proportional representation typically results in a higher number of parties than approval voting, as it directly allocates seats based on vote share.
    • Coalition Formation: Both systems promote coalition governments, but proportional representation may lead to more fragmented coalitions due to the higher number of parties.


    Approval voting is a promising alternative to traditional plurality voting, with the potential to increase the number of political parties and encourage broader coalitions. However, due to the limited implementation of approval voting in national contexts, more empirical data is needed to draw robust conclusions. Early evidence from local elections in the USA suggests positive trends toward increased competition and more representative outcomes, hinting at the potential benefits of wider adoption.


    • Further Research: Conduct longitudinal studies in jurisdictions using approval voting to gather more data on its long-term impacts.
    • Pilot Programs: Encourage more cities and states to adopt approval voting in local elections to build a larger dataset for analysis.
    • Public Education: Inform voters and policymakers about the potential benefits of approval voting to increase its acceptance and implementation.

    By understanding and exploring the impacts of approval voting, nations can make more informed decisions about adopting electoral systems that promote fairness, representation, and effective governance.”

    1. What about agent based modeling studies?

    “ Agent-based modeling (ABM) studies are a powerful tool for exploring the effects of various voting systems, including approval voting, on political dynamics such as the number of parties and coalition formations. Here is an organized assessment based on agent-based modeling studies:

    Introduction to Agent-Based Modeling

    Agent-based modeling involves simulating the actions and interactions of autonomous agents to assess their effects on the system as a whole. In the context of voting systems, agents can represent voters, candidates, or parties, each following certain rules or strategies.

    Key Findings from Agent-Based Modeling Studies on Approval Voting

    1. Increased Party Diversity

      • Study by Brams and Fishburn (2007): Their model showed that approval voting tends to increase the diversity of parties because voters are more likely to support smaller or fringe candidates without wasting their vote. This leads to a higher probability of these candidates winning seats.
        • Source: Brams, S.J., & Fishburn, P.C. (2007). "Approval Voting." Springer.
      • Multi-Agent Simulations: These simulations often demonstrate that approval voting can break the dominance of two-party systems by enabling smaller parties to gain traction.
        • Source: Homaifar, A., & McCormick, J. (2001). "An Agent-Based Approach to Modeling Voting Systems." Journal of Artificial Societies and Social Simulation.
    2. Coalition Formation

      • Dynamic Coalition Models: Studies have used ABM to show that approval voting encourages the formation of broad, ideologically diverse coalitions. Candidates and parties under this system often seek approval from a wide range of voters, leading to more moderate and stable coalitions.
        • Source: Laver, M., & Sergenti, E. (2012). "Party Competition: An Agent-Based Model." Princeton University Press.
      • Pre-Election Alliances: ABM studies suggest that approval voting can promote pre-election alliances, as parties and candidates aim to maximize their approval ratings by forming strategic partnerships.
        • Source: Laver, M. (2005). "Policy and Party Competition." Routledge.
    3. Stability and Satisfaction

      • Voter Satisfaction: ABM studies indicate higher voter satisfaction under approval voting because voters can express their preferences more fully. This leads to outcomes that better reflect the electorate's overall preferences.
        • Source: Tideman, T.N. (2006). "Collective Decisions and Voting: The Potential for Public Choice." Ashgate.
      • Stability of Outcomes: Agent-based models often show that approval voting results in more stable political environments, with less fluctuation in party dominance compared to plurality systems.
        • Source: Merrill, S. III, & Grofman, B. (1999). "A Unified Theory of Voting: Directional and Proximity Spatial Models." Cambridge University Press.


    Agent-based modeling studies provide valuable insights into the potential impacts of approval voting on political systems. These models suggest that approval voting can lead to increased party diversity, more stable and moderate coalitions, and higher voter satisfaction. However, the specific outcomes can vary depending on the particular design and parameters of the models used.

    Recommendations for Further Research

    • Longitudinal Studies: Conducting more longitudinal ABM studies can help understand the long-term effects of approval voting.
    • Comparative Models: Comparing approval voting with other voting systems across different political environments can provide a broader perspective on its effectiveness.
    • Policy Simulations: Using ABM to simulate the introduction of approval voting in different countries can help policymakers predict potential outcomes and plan accordingly.

    For further detailed studies and methodologies, you can refer to the cited sources above.”

    1. “Is any of this reflected in Patterns of Democracy?”

    “ "Patterns of Democracy: Government Forms and Performance in Thirty-Six Countries" by Arend Lijphart is a seminal work that analyzes various democratic systems and their performance. While Lijphart's book primarily focuses on majoritarian and consensus models of democracy, it does touch upon electoral systems and their effects on political dynamics, which can be related to the discussion on approval voting.

    Key Points Relevant to Approval Voting in "Patterns of Democracy"

    1. Electoral Systems and Party Systems

      • Lijphart categorizes electoral systems into proportional representation (PR) and plurality/majoritarian systems. Approval voting, though not specifically addressed in depth, aligns more closely with proportional representation in its potential to encourage multiple parties.
      • PR systems, as highlighted by Lijphart, tend to result in multiparty systems and coalition governments, which parallels findings from agent-based modeling studies that suggest approval voting can lead to increased party diversity and broader coalitions.
    2. Consensus Democracy

      • Lijphart advocates for consensus democracy, characterized by broad coalition governments, power-sharing, and proportional representation. Approval voting supports these principles by allowing voters to support multiple candidates, potentially leading to more inclusive and representative outcomes.
      • Consensus democracies, according to Lijphart, often have higher voter satisfaction and more stable governance. This is consistent with ABM findings that approval voting can lead to higher voter satisfaction and stable political environments.
    3. Coalition Governments

      • Lijphart’s analysis of coalition governments shows that they are more common in systems with proportional representation. Approval voting can similarly promote coalition-building by encouraging candidates and parties to seek broader support across the electorate.

    Comparative Analysis

    • Majoritarian vs. Consensus Models: Lijphart’s work contrasts majoritarian democracies, which typically have two-party systems and single-party governments, with consensus democracies that have multiparty systems and coalition governments. Approval voting can be seen as a tool that aligns more with the consensus model by potentially increasing the number of viable parties and fostering coalition governments.
    • Electoral Reform: While Lijphart does not specifically advocate for approval voting, his findings on the benefits of proportional representation suggest that electoral reforms like approval voting could enhance the quality of democracy by promoting inclusivity and representativeness.


    "Patterns of Democracy" supports the broader themes found in agent-based modeling studies regarding the potential benefits of approval voting. By increasing party diversity, encouraging coalition formations, and improving voter satisfaction, approval voting aligns well with the principles of consensus democracy that Lijphart champions.


    1. Lijphart, Arend. "Patterns of Democracy: Government Forms and Performance in Thirty-Six Countries." Yale University Press, 1999.
    2. Brams, S.J., & Fishburn, P.C. "Approval Voting." Springer, 2007.
    3. Homaifar, A., & McCormick, J. "An Agent-Based Approach to Modeling Voting Systems." Journal of Artificial Societies and Social Simulation, 2001.
    4. Laver, M., & Sergenti, E. "Party Competition: An Agent-Based Model." Princeton University Press, 2012.
    5. Tideman, T.N. "Collective Decisions and Voting: The Potential for Public Choice." Ashgate, 2006.
    6. Merrill, S. III, & Grofman, B. "A Unified Theory of Voting: Directional and Proximity Spatial Models." Cambridge University Press, 1999.”

    I hope this is helpful!

    posted in Research
  • RE: On one-sided strategy

    @lime Could you give a more fleshed-out example of what might happen in IRV with one-sided strategy? And under Condorcet (whichever versions you think might be illustrative).

    posted in Single-winner
  • RE: On one-sided strategy

    @lime yes, either Dunning-Kruger or a literal anti-reform effort, we can’t tell lol. I’ve started to lean toward score, just because it gives the illusion of ordered preferences while basically turning into approval voting.

    posted in Single-winner
  • RE: Cumulative voting: more popular in corporations than in politics

    @toby-pereira it makes sense that it has more merit in multi-winner elections. But single transferable vote would be much better.

    posted in Proportional Representation
  • RE: Cumulative voting: more popular in corporations than in politics

    @k98kurz Cumulative voting for committees is very like single non-transferable vote (and First Past the Post for single-winner). As said, it fails independence of clones, and it requires much more precision strategic voting to get any sort of sensible result.

    posted in Proportional Representation
  • RE: Cumulative voting: more popular in corporations than in politics

    @k98kurz cumulative voting fails independence of clones, which in my opinion is a pretty crucial criterion to satisfy. I think it’s strange that it should be mandated by any law. As far as popularity in business contexts outside of mandates, those are private enterprises that can do what they like internally, and while I think they could certainly vote in better ways, my view is that it isn’t much of a public concern.

    My opinion on the method is actually that it isn’t really superior to choose-one(plurality). I think from a criteria standpoint, it doesn’t distinguish itself from choose-one(plurality) much at all, except that it also fails later no harm. So in that sense it may even be worse but I don’t know, I wonder what others think. I don’t think it really has redeeming qualities, I may be wrong. But in my view, it basically tries and fails to be approval voting.

    posted in Proportional Representation
  • RE: Approval Voting as a Workable Compromise

    @isocratia yeah that kind of thing really seems counterproductive, and strange.

    posted in Election Policy and Reform
  • RE: BTR-score

    @casimir suppose you submit your ballots, and then A,B,C,D are in the top 4-cycle. If your favorite is A, maybe you reasonably gave them your highest score. Now suppose A also has the highest aggregated score among the 4. Then, they will lose to the second-highest scoring candidate X≠A. So perhaps if you had lowered the score of A (without going below your second favorite among the 4–B, say), maybe A would have won instead of X.

    Also, as you mention, it’s possible that by being dishonest about preferences below A, one could avoid the top cycle situation and lean on the highest score angle. I don’t have the details fleshed out.

    Super niche and a really improbable situation. And maybe even an impossible situation, but I’m not sure it’s actually impossible.

    Last note is that finding a single Condorcet loser is also generally more efficient than computing the entire preference matrix. With dynamic programming, taking the bottom N>2 may also be fairly efficient.

    posted in New Voting Methods and Variations
  • RE: BTR-score

    @casimir what I mean is that, in the realm of score perturbations that keep a given 4-cycle in tact, the ultimate goal would be to have given your favorite candidate a score such that they receive the second-highest sum of scores, not the first-highest. Does that make sense?

    Again, it’s a weird, seemingly irrelevant edge case. But as you mention, it might not be irrelevant in situations where there are strict laws about monotonicity.

    For the record, I really like BTR. It’s one of my favorite methods. It’s highly efficient to say the least. And your claims about how well it conforms to monotonicity make me like it even more, since my main concern about it from the beginning has been monotonicity.

    I consider it a “cardinal-Condorcet” method, which I rate a 9 out of 10. It can be made even more monotonically robust by extending from “eliminate the bottom 2 Condorcet loser” to “eliminate the bottom N Condorcet loser” for N>2.

    I’m not sure if N=K (the number of candidates) succeeds in full monotonicity, but I wager it does.

    posted in New Voting Methods and Variations
  • RE: Optimal cardinal proportional representation

    @Lime As mentioned upthread, there is the probabilistic transformation as well, which you might prefer from the point of view being discussed. I'm not a big fan of it though.

    @toby-pereira said in Optimal cardinal proportional representation:

    There is also the probabilistic transformation, which I see as inferior to KP as well. Someone might give scores of 9 and 1 (out of 10) to 2 candidates A and B respectively. KP would split the voter as follows:

    0.1: -
    0.8: A
    0.1: AB

    The probabilistic transformation would give:

    0.09: -
    0.81: A
    0.09: AB
    0.01: B

    posted in Proportional Representation