# The distortion of distributed voting

@article{FilosRatsikas2019TheDO, title={The distortion of distributed voting}, author={Aris Filos-Ratsikas and Evi Micha and Alexandros A. Voudouris}, journal={ArXiv}, year={2019}, volume={abs/1905.01882} }

Voting can abstractly model any decision-making scenario and as such it has been extensively studied over the decades. Recently, the related literature has focused on quantifying the impact of utilizing only limited information in the voting process on the societal welfare for the outcome, by bounding the distortion of voting rules. Even though there has been significant progress towards this goal, all previous works have so far neglected the fact that in many scenarios (like presidential… Expand

#### 7 Citations

Awareness of Voter Passion Greatly Improves the Distortion of Metric Social Choice

- Computer Science
- WINE
- 2019

We develop new voting mechanisms for the case when voters and candidates are located in an arbitrary unknown metric space, and the goal is to choose a candidate minimizing social cost: the total… Expand

Peeking Behind the Ordinal Curtain: Improving Distortion via Cardinal Queries

- Computer Science
- AAAI
- 2020

This paper designs new deterministic mechanisms that achieve significantly improved distortion bounds and, in many cases, outperform the best-known randomized ordinal mechanisms. Expand

Characterizing plurality using the majoritarian condition: a new proof and implications for other scoring rules

- Computer Science
- 2020

A proof by contradiction approach is adopted to show that plurality is the only scoring rule satisfying the majoritarian principle, and the relationship that majoritarianism implies faithfulness is used to present a new proof allowing us to derive limits on the size of the group for which a particular scoring rule will satisfymajoritarianism without restricting voter preferences. Expand

Ordinal Approximation for Social Choice, Matching, and Facility Location Problems Given Candidate Positions

- Computer Science
- ACM Trans. Economics and Comput.
- 2021

In this work, we consider general facility location and social choice problems, in which sets of agents A and facilities F are located in a metric space, and our goal is to assign agents to… Expand

Distortion in Social Choice Problems: The First 15 Years and Beyond

- Computer Science, Economics
- IJCAI
- 2021

The most significant results of the literature on distortion from the past 15 years are surveyed, and important open problems and the most promising avenues of ongoing and future work are highlighted. Expand

Approximate mechanism design for distributed facility location

- Computer Science
- SAGT
- 2021

This work considers the distributed facility location problem, in which there is a set of agents positioned on the real line, who are also partitioned into multiple symmetric districts, and paints an almost complete picture of the distortion landscape of distributed mechanisms. Expand

Resolving the Optimal Metric Distortion Conjecture

- Mathematics, Computer Science
- 2020 IEEE 61st Annual Symposium on Foundations of Computer Science (FOCS)
- 2020

A novel lemma about matching voters to candidates is proved, which is referred to as the ranking-matching lemma, and a new randomized algorithm is introduced with improved distortion compared to known results, and improved lower bounds on the distortion of all deterministic and randomized algorithms are provided. Expand

#### References

SHOWING 1-10 OF 31 REFERENCES

Approval-Based Elections and Distortion of Voting Rules

- Computer Science
- IJCAI
- 2019

This work defines acceptability-distortion for a number of rules, including Plurality, Borda, $k$-Approval, Veto, the Copeland's rule, Ranked Pairs, the Schulze's method, and STV, and compute the distortion of Approval Voting. Expand

Divide and Conquer: Using Geographic Manipulation to Win District-Based Elections

- Computer Science
- AAMAS
- 2017

It is shown that many parties are potentially able to make themselves victorious using district manipulation, and that the relevant variables here go beyond share of the vote; the form of geographic dispersion also plays a crucial role. Expand

Awareness of Voter Passion Greatly Improves the Distortion of Metric Social Choice

- Computer Science
- WINE
- 2019

We develop new voting mechanisms for the case when voters and candidates are located in an arbitrary unknown metric space, and the goal is to choose a candidate minimizing social cost: the total… Expand

Voting almost maximizes social welfare despite limited communication

- Computer Science
- Artif. Intell.
- 2010

The notion of embeddings into voting rules: functions that receive an agent's utility function and return the agent's vote are presented and it is established that very low distortion can be obtained using randomizedembeddings, especially when the number of agents is large compared to thenumber of alternatives. Expand

Truthful and Near-Optimal Mechanisms for Welfare Maximization in Multi-Winner Elections

- Computer Science
- AAAI
- 2018

The utilitarian social welfare of mechanisms for preference aggregation, measured by the distortion, is considered and it is shown that for a particular input format called threshold approval voting, there is a mechanism with nearly optimal distortion when the number of voters is large. Expand

The Distortion of Cardinal Preferences in Voting

- Computer Science
- CIA
- 2006

It is argued that, whenever voting is applied in a multiagent system, distortion must be a pivotal consideration. Expand

Misrepresentation in District Voting

- Computer Science
- IJCAI
- 2016

The Misrepresentation Ratio is defined which quantifies the deviation from proportional representation in a district-based election, and bounds for this ratio under various voting rules are provided. Expand

Improved Metric Distortion for Deterministic Social Choice Rules

- Computer Science
- EC
- 2019

This paper designs an ordinal social choice rule with minimum distortion, which is the worst-case ratio, over all consistent metrics, between the social cost of the rule and that of the optimal omniscient rule with knowledge of the underlying metric space, and proposes a new voting rule via an alternative generalization of uncovered sets. Expand

More Natural Models of Electoral Control by Partition

- Computer Science, Mathematics
- ADT
- 2015

It is the hope that having these new partition types will allow studies of control attacks to include such models that more realistically capture many settings, and for some important cases analyze the complexity of these models. Expand

Relating Metric Distortion and Fairness of Social Choice Rules

- Computer Science, Mathematics
- NetEcon@SIGMETRICS
- 2018

It is proved that the distinct notions of distortion and fairness ratio are in fact closely linked -- within an additive factor of 2 for any voting rule -- and thus STV also achieves an $O(\log m)$ fairness ratio. Expand